<PAGE>   1

                                                                   EXHIBIT 4.2

                                                                CONFORMED COPY
                                SECOND AMENDMENT
                               TO CREDIT AGREEMENT

         THIS SECOND AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), dated as
of August 4, 2000, is by and among Gaylord Container Corporation, a Delaware
corporation (the "Borrower"), the undersigned financial institutions in their
capacities as lenders (collectively, the "Lenders"), and Bankers Trust Company,
as agent (the "Agent") for the Lenders.

                              W I T N E S S E T H :
                              - - - - - - - - - -

         WHEREAS, the Borrower, the Lenders and the Agent are parties to that
certain Credit Agreement dated as of June 19, 1998 (as amended, restated,
supplemented or otherwise modified and in effect from time to time, the "Credit
Agreement"), pursuant to which the Lenders have provided to the Borrower credit
facilities and other financial accommodations; and

         WHEREAS, the Borrower has requested that the Agent and the Lenders
amend the Credit Agreement in certain respects as set forth herein and the
Lenders and the Agent are agreeable to the same, subject to the terms and
conditions hereof;

         NOW, THEREFORE, in consideration of the premises and of the mutual
covenants contained herein, and other good and valuable consideration the
receipt and adequacy of which are hereby acknowledged, the parties hereto hereby
agree as follows:

         1. Defined Terms. Terms capitalized herein and not otherwise defined
herein are used with the meanings ascribed to such terms in the Credit
Agreement.

         2. Amendments to Credit Agreement. The Credit Agreement is, as of the
Effective Date (as defined below), hereby amended as follows:

                  (a) Section 1.1 of the Credit Agreement is amended by (i)
deleting the percentage "2.25%" now appearing in clause (ii) of the definition
of "Applicable Base Rate Margin" and substituting the phrase "the applicable
percentage set forth in the following table under the column Applicable Base
Rate Margin for Term Loans opposite the Most Recent Ratio of Total Debt to
EBITDA as of such date" therefor, and (ii) deleting the table now appearing at
the end of the definition of "Applicable Base Rate Margin" and substituting
therefor the following:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------
         MOST RECENT                          APPLICABLE BASE RATE      APPLICABLE BASE RATE
         RATIO OF TOTAL DEBT                       MARGIN FOR                MARGIN FOR
         TO EBITDA                              REVOLVING LOANS              TERM LOANS
--------------------------------------------------------------------------------------------
<S>                                                  <C>                       <C>
Less than 3.00 to 1.00                               1.00%                     2.25%
--------------------------------------------------------------------------------------------
Equal to or greater than 3.00 to 1.00 but
less than 3.50 to 1.00                               1.25%                     2.25%
--------------------------------------------------------------------------------------------
Equal to or greater than 3.50 to 1.00 but
less than 4.00 to 1.00                               1.50%                     2.25%
--------------------------------------------------------------------------------------------
</TABLE>



<PAGE>   2




<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------
         MOST RECENT                          APPLICABLE BASE RATE      APPLICABLE BASE RATE
         RATIO OF TOTAL DEBT                       MARGIN FOR                MARGIN FOR
         TO EBITDA                              REVOLVING LOANS              TERM LOANS
--------------------------------------------------------------------------------------------
<S>                                                  <C>                       <C>
Equal to or greater than 4.00 to 1.00 but
less than 4.50 to 1.00                               1.75%                     2.25%
--------------------------------------------------------------------------------------------
Equal to or greater than 4.50 to 1.00 but
less than 5.00 to 1.00                               2.00%                     2.25%
--------------------------------------------------------------------------------------------
Equal to or greater than 5.00 to 1.00 but
less than 5.50 to 1.00                               2.25%                     2.25%
--------------------------------------------------------------------------------------------
Equal to or greater than 5.50 to 1.00 but
less than 6.00 to 1.00                               2.50%                     2.50%
--------------------------------------------------------------------------------------------
Greater than or equal to 6.00 to 1.00
                                                     2.625%                    2.625%
--------------------------------------------------------------------------------------------
</TABLE>

                  (b) Section 1.1 of the Credit Agreement is further amended by
(i) deleting the percentage "3.25%" now appearing in clause (ii) of the
definition of "Applicable Eurodollar Rate Margin" and substituting the phrase
"the applicable percentage set forth in the following table under the column
Applicable Eurodollar Rate Margin for Term Loans opposite the Most Recent Ratio
of Total Debt to EBITDA as of such date" therefor, and (ii) deleting the table
now appearing at the end of the definition of "Applicable Eurodollar Rate
Margin" and substituting therefor the following:

<TABLE>
<CAPTION>

----------------------------------------------------------------------------------------------------
         MOST RECENT                       APPLICABLE EURODOLLAR RATE     APPLICABLE EURODOLLAR RATE
         RATIO OF TOTAL DEBT               MARGIN FOR REVOLVING LOANS             MARGIN FOR
         TO EBITDA                                                                TERM LOANS
----------------------------------------------------------------------------------------------------
<S>                                                  <C>                              <C>

Less than 3.00 to 1.00                                2.00%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 3.00 to 1.00 but
less than 3.50 to 1.00                                2.25%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 3.50 to 1.00 but
less than 4.00 to 1.00                                2.50%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 4.00 to 1.00 but
less than 4.50 to 1.00                                2.75%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 4.50 to 1.00 but
less than 5.00 to 1.00                                3.00%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 5.00 to 1.00 but
less than 5.50 to 1.00                                3.25%                           3.25%
----------------------------------------------------------------------------------------------------
Equal to or greater than 5.50 to 1.00 but
less than 6.00 to 1.00                                3.50%                           3.50%
----------------------------------------------------------------------------------------------------
Greater than or equal to 6.00 to 1.00                3.625%                          3.625%
----------------------------------------------------------------------------------------------------
</TABLE>


                  (c) Section 1.1 of the Credit Agreement is further amended by
deleting the last two sentences now appearing in the definition of "Consolidated
Net Income" and substituting therefor the following:



                                      -2-



<PAGE>   3


         "There shall be excluded in computing Consolidated Net Income any gain
         or loss which must be treated as an extraordinary item under GAAP or
         any gain or loss realized upon the sale or other disposition of any
         real property or equipment that is not sold in the ordinary course of
         business or of any capital stock of the Person or a Subsidiary of the
         Person."

                  (d) Section 1.1 of the Credit Agreement is further amended by
deleting the ratio "5.00 to 1.0" now appearing in the definition of "Most Recent
Ratio of Total Debt to EBITDA" and substituting the ratio "6.00 to 1.00"
therefor.

                  (e) Section 1.1 of the Credit Agreement is further amended by
adding thereto (in alphabetical order) the following new defined term:

         ""Net Debt Reduction" means that the aggregate amount of Indebtedness
         of Borrower and its Subsidiaries outstanding as of December 31, 2001
         (as reported in the certificate of a Responsible Officer delivered
         pursuant to Section 7.2(b) for the fiscal quarter ended on such date)
         is less than the aggregate amount of Indebtedness of Borrower and its
         Subsidiaries as of June 30, 2000 by an amount equal to or greater than
         $100,000,000; provided, however, that any reduction in Indebtedness
         shall be excluded from the foregoing calculation to the extent that
         such reduction is not permanent in nature and any reduction in
         outstanding Indebtedness under revolving lines of credit, including the
         Revolving Facility, shall be excluded unless there is a corresponding
         permanent reduction in outstanding commitments."

                  (f) Section 4.4(c) of the Credit Agreement is amended by
deleting the clause "On the first Business Day" and subsituting therefor "Within
five (5) Business Days."

                  (g) Section 8.4(b) of the Credit Agreement is amended by
deleting clause (ii) thereof in its entirety and substituting therefor the
following:

         "(ii) make other Asset Dispositions with respect to assets of Borrower
         and its Subsidiaries, provided that each such sale is for at least the
         fair market value of such assets (as determined in good faith (a) for
         Asset Dispositions not in excess of $5,000,000 by a Responsible Officer
         of Borrower and (b) for Asset Dispositions equal to or more than
         $5,000,000 by the board of directors of Borrower) (provided that all or
         any portion of the consideration for such sale may be in the form of
         the exchange of new or replacement property for the assets so sold as
         long as the fair market value of such newly acquired property and any
         cash received in such sale is at least equal to the fair market value
         of such assets sold); provided, further, that the Net Sale Proceeds
         from any such Asset Dispositions are applied in the manner set forth in
         Section 4.4(c)"

                   (h) Section 9.2 of the Credit Agreement is amended by
deleting such Section in its entirety and substituting therefor the following:



                                      -3-



<PAGE>   4


          "9.2 Minimum Consolidated EBITDA. Permit the Consolidated EBITDA of
         Borrower and its Subsidiaries (a) to be less than (i) $14,000,000 for
         the one fiscal quarter ending September 30, 1998, (ii) $26,000,000 for
         the two fiscal quarter period ending December 31, 1998 and (iii)
         $28,000,000 for the three fiscal quarter period ending March 31, 1999,
         and (b) for the applicable Test Period ending on a date set forth below
         to be less than the amount set for the opposite such date:

                  Date                         Minimum Consolidated EBITDA
                  ----                         ---------------------------

         June 30, 1999                               $37,000,000
         September 30, 1999                          $47,000,000
         December 31, 1999                           $58,000,000
         March 31, 2000                              $88,000,000
         June 30, 2000                               $110,000,000
         September 30, 2000                          $115,000,000
         December 31, 2000                           $115,000,000
         March 31, 2001                              $105,000,000
         June 30, 2001                               $100,000,000
         September 30, 2001                          $100,000,000
         December 31, 2001 and
         each fiscal quarter thereafter              $150,000,000

         provided, however, that if a Net Debt Reduction occurs as of December
         31, 2001, Borrower shall be permitted to satisfy the minimum
         Consolidated EBITDA requirement under this Section 9.2 for the Test
         Periods ending December 31, 2001, March 31, 2002, June 30, 2002 and
         September 30, 2002 by maintaining Consolidated EBITDA of Borrower and
         its Subsidiaries of not less than $35,000,000 for the one fiscal
         quarter ending December 31, 2001, $37,500,000 for the one fiscal
         quarter ending March 31, 2002, $37,500,000 for the one fiscal quarter
         ending June 30, 2002 and $37,500,000 for the one fiscal quarter ending
         September 30, 2002, respectively."

                  (i) Section 9.3 of the Credit Agreement is hereby amended by
deleting such Section in its entirety and substituting therefor the following:

         "9.3 Interest Coverage Ratio. Permit the Interest Coverage Ratio (a) to
         be less than (i) 0.60 to 1.00 for the one fiscal quarter ending
         September 30, 1998, (ii) 0.65 to 1.00 for the two fiscal quarter period
         ending December 31, 1998 and (iii) .45 to 1.00 for the three fiscal
         quarter period ending March 31, 1999, and (b) for the applicable Test
         Period ending on a date set forth below to be less than the ratio set
         forth opposite such date:

         Date                                        Ratio
         ----                                        -----

         June 30, 1999                               0.45 to 1.00
         September 30, 1999                          0.55 to 1.00
         December 31, 1999                           0.65 to 1.00



                                       -4-


<PAGE>   5



         March 31, 2000                              1.00 to 1.00
         June 30, 2000                               1.25 to 1.00
         September 30, 2000                          1.25 to 1.00
         December 31, 2000                           1.25 to 1.00
         March 31, 2001                              1.15 to 1.00
         June 30, 2001                               1.00 to 1.00
         September 30, 2001                          1.00 to 1.00
         December 31, 2001 and
         each fiscal quarter thereafter              1.75 to 1.00

         provided, however, that if a Net Debt Reduction occurs as of
December 31, 2001, Borrower shall be permitted to satisfy the minimum Interest
Coverage Ratio requirement under this Section 9.3 for the Test Periods ending
December 31, 2001, March 31, 2002, June 30, 2002 and September 30, 2002 by
maintaining an Interest Coverage Ratio of not less than 1.50 to 1.00 for the one
fiscal quarter ending December 31, 2001, 1.75 to 1.00 for the one fiscal quarter
ending March 31, 2002, 1.75 to 1.00 for the one fiscal quarter ending June 30,
2002 and 1.75 to 1.00 for the one fiscal quarter ending September 30, 2002,
respectively."

         3. Changes in Interest Rates and Fees. The Borrower, the Lenders and
the Agent acknowledge and agree that any increases in any interest rates or fees
resulting from the effectiveness of this Amendment shall be effective as of the
earlier to occur of (i) August 15, 2000 and (ii) the date on which the Borrower
delivers unaudited financial statements for the fiscal quarter ending June 30,
2000 pursuant to Section 7.1(a) of the Credit Agreement.

         4. Amendment Fee. In consideration of the execution of this Amendment
by the Agent and the Lenders, the Borrower hereby agrees to pay each Lender
which executes this Amendment on or prior to August 4, 2000 a fee (the
"Amendment Fee") in an amount equal to such Lender's Commitment multiplied by
0.25%.

         5. Borrower's Representations and Warranties. In order to induce the
Agent and the Lenders to enter into this Amendment, the Borrower hereby
represents and warrants to the Agent and the Lenders, in each case after giving
effect to this Amendment, as follows:

                  (a) The Borrower has the right, power and capacity and has
been duly authorized and empowered by all requisite corporate and shareholder
action to enter into, execute, deliver and perform this Amendment and all
agreements, documents and instruments executed and delivered pursuant to this
Amendment.

                  (b) This Amendment constitutes the Borrower's legal, valid and
binding obligation, enforceable against it, except as enforcement thereof may be
subject to the effect of any applicable bankruptcy, insolvency, reorganization,
moratorium or similar laws affecting creditors' rights generally and general
principles of equity (regardless of whether such enforcement is sought in a
proceeding in equity or at law or otherwise).

                  (c) The representations and warranties contained in the Credit
Agreement and the other Loan Documents are true and correct in all material
respects at and as of the Effective Date as though made on and as of the
Effective Date (except to the extent specifically made with



                                      -5-



<PAGE>   6




regard to a particular date, in which case such representation and warranty is
true and correct in all material respects as of such earlier date).

                  (d) The Borrower's execution, delivery and performance of this
Amendment do not and will not violate its Certificate of Incorporation or
By-laws, any law, rule, regulation, order, writ, judgment, decree or award
applicable to it or any contractual provision to which it is a party or to which
it or any of its property is subject.

                  (e) No authorization or approval or other action by, and no
notice to or filing or registration with, any governmental authority or
regulatory body (other than those which have been obtained and are in force and
effect) is required in connection with its execution, delivery and performance
of this Amendment and all agreements, documents and instruments executed and
delivered pursuant to this Amendment.

                  (f) No Event of Default or Unmatured Event of Default exists
under the Credit Agreement or would exist after giving effect to the
transactions contemplated by this Amendment.

         6. Conditions to  Effectiveness  of Amendment.  This Amendment shall
become effective on the date (the "Effective Date") each of the following
conditions precedent is satisfied:


                  (a) Execution and Delivery.  The Borrower, the Agent, and
the Required Lenders shall have executed and delivered this Amendment.

                  (b) No  Defaults.  No Unmatured Event of Default or Event
of Default under the Credit Agreement (as amended hereby) shall have occurred
and be continuing.

                  (c) Representations and Warranties. After giving effect to the
amendments and consents contemplated by this Amendment, the representations and
warranties of the Borrower contained in this Amendment, the Credit Agreement and
the other Loan Documents shall be true and correct in all material respects as
of the Effective Date, with the same effect as though made on such date, except
to the extent that any such representation or warranty relates to an earlier
date, in which case such representation or warranty shall be true and correct in
all material respects as of such earlier date.

                  (d) Officer's Certificate. The Borrower shall have duly
executed and delivered to the Agent a certificate of a Responsible Officer of
the Borrower dated as of the Effective Date in the form of Exhibit A attached
hereto.

                  (e) Payment of Amendment Fee. The Borrower shall have paid in
full to the Agent, for ratable distribution to those Lenders that have signed
this Amendment on or prior to August 4, 2000, an amount equal to the Amendment
Fee; provided, however, that the Amendment Fee shall be payable only in the
event that this Amendment has been executed by the Agent and the Required
Lenders.

         7.  Miscellaneous.  The parties hereto hereby further agree as
follows:


                                      -6-


<PAGE>   7


                  (a) Costs, Expenses and Taxes. The Borrower hereby agrees to
pay all reasonable fees, costs and expenses of the Agent incurred in connection
with the negotiation, preparation and execution of this Amendment and the
transactions contemplated hereby, including, without limitation, the reasonable
fees and expenses of Winston & Strawn, counsel to the Agent.

                  (b) Counterparts. This Amendment may be executed in one or
more counterparts, each of which, when executed and delivered, shall be deemed
to be an original and all of which counterparts, taken together, shall
constitute but one and the same document with the same force and effect as if
the signatures of all of the parties were on a single counterpart, and it shall
not be necessary in making proof of this Amendment to produce more than one (1)
such counterpart.

                  (c) Headings.  Headings used in this Amendment are for
convenience of reference only and shall not affect the construction of this
Amendment.

                  (d) Integration. This Amendment and the Credit Agreement (as
amended hereby) constitute the entire agreement among the parties hereto with
respect to the subject matter hereof.

                  (e) Governing Law. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS AND DECISIONS OF
THE STATE OF NEW YORK (WITHOUT REFERENCE TO CONFLICT OF LAWS PRINCIPLES).

                  (f) Binding Effect. This Amendment shall be binding upon and
inure to the benefit of and be enforceable by the Borrower, the Agent and the
Lenders and their respective successors and assigns. Except as expressly set
forth to the contrary herein, this Amendment shall not be construed so as to
confer any right or benefit upon any Person other than the Borrower, the Agent
and the Lenders and their respective successors and permitted assigns.

                  (g) Amendment; Waiver. The parties hereto agree and
acknowledge that nothing contained in this Amendment in any manner or respect
limits or terminates any of the provisions of the Credit Agreement or any of the
other Loan Documents other than as expressly set forth herein and further agree
and acknowledge that the Credit Agreement (as amended hereby) and each of the
other Loan Documents remain and continue in full force and effect and are hereby
ratified and confirmed. Except to the extent expressly set forth herein, the
execution, delivery and effectiveness of this Amendment shall not operate as a
waiver of any rights, power or remedy of the Lenders or the Agent under the
Credit Agreement or any other Loan Document, nor constitute a waiver of any
provision of the Credit Agreement or any other Loan Document. No delay on the
part of any Lender or the Agent in exercising any of their respective rights,
remedies, powers and privileges under the Credit Agreement or any of the Loan
Documents or partial or single exercise thereof, shall constitute a waiver
thereof. None of the terms and conditions of this Amendment may be changed,
waived, modified or varied in any manner, whatsoever, except in accordance with
Section 12.1 of the Credit Agreement.

                            [signature pages follow]


                                      -7-

<PAGE>   8



         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed by their respective officers thereunto duly authorized, as of the date
first written above.


                                      GAYLORD CONTAINER CORPORATION



                                      By:  /s/ Thomas M. Steffen
                                           ------------------------------------
                                      Name:  Thomas M. Steffen
                                             ----------------------------------
                                      Title:  Assistant Treasurer
                                              ---------------------------------


                                      BANKERS TRUST COMPANY, in its individual
                                               capacity and as Agent


                                      By:  /s/ M. A. Orlando
                                           ------------------------------------
                                      Name:  M. A. Orlando
                                             ----------------------------------
                                      Title:  Principal
                                              ---------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   9





                                      BEAR STEARNS INVESTMENT
                                      PRODUCTS, INC.


                                      By:  /s/ G. Hanley
                                           ------------------------------------
                                      Name:  G. Hanley
                                             ----------------------------------
                                      Title:  Authorized Officer
                                              ---------------------------------



                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT



<PAGE>   10





                                      BANK OF AMERICA, N.A.


                                      By:
                                           ------------------------------------
                                      Name:
                                             ----------------------------------
                                      Title:
                                              ---------------------------------





                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   11





                                      BANKBOSTON, N.A.


                                      By:
                                           ------------------------------------
                                      Name:
                                             ----------------------------------
                                      Title:
                                              ---------------------------------


                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   12





                                 BLACK DIAMOND CLO 1998-1 LTD.
                                 By: Black Diamond Capital Management, L.L.C.,
                                            as Collateral Manager


                                 By:  /s/ J. H. Cullinane
                                      ----------------------------------------
                                 Name:  John H. Cullinane
                                        --------------------------------------
                                 Title:  Director
                                         -------------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT



<PAGE>   13





                                BLACK DIAMOND CLO 2000-1 LTD.
                                By: Black Diamond Capital Management, L.L.C.,
                                           as Collateral Manager


                                By:  /s/ D. D.
                                     ----------------------------------------
                                Name:  David Dyer
                                       --------------------------------------
                                Title:  Director
                                        -------------------------------------





                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   14





                                CHRISTIANIA BANK


                                By:
                                     ------------------------------------------
                                Name:
                                       ----------------------------------------
                                Title:
                                        ---------------------------------------

                                By:
                                     ------------------------------------------
                                Name:
                                       ----------------------------------------
                                Title:
                                        ---------------------------------------



                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   15




                                EATON VANCE SENIOR INCOME TRUST
                                By: Eaton Vance Management as Investment
                                       Advisor


                                By:  /s/ Payson Swaffield
                                     ------------------------------------------
                                Name:  Payson F. Swaffield
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------


                                SENIOR DEBT PORTFOLIO
                                By: Boston Management and Research as
                                       Investment Advisor


                                By:  /s/ Payson Swaffield
                                     ------------------------------------------
                                Name:  Payson F. Swaffield
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   16






                                FLEET BUSINESS CREDIT CORPORATION


                                By:  /s/ Thomas Maiale
                                     ------------------------------------------
                                Name:  Thomas Maiale
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------


                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   17





                                FOOTHILL CAPITAL CORPORATION


                                By:  /s/ Sean Dixon
                                     ------------------------------------------
                                Name:  Sean T. Dixon
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------





                                FOOTHILL INCOME TRUST II LP
                                By:  FIT II GP LLC, its General Partner


                                By:  /s/ Dennis R. Ascher
                                     ------------------------------------------
                                Name:  Dennis R. Ascher
                                       ----------------------------------------
                                Title:  Managing Member
                                        ---------------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT




<PAGE>   18





                                FLEET NATIONAL BANK,
                                as Trust Administrator for
                                LONG LANE MASTER TRUST IV


                                By:  /s/ R. Ross Nadler
                                     ------------------------------------------
                                Name:  R. Ross
                                       ----------------------------------------
                                Title:  Authorized Officer
                                        ---------------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   19





                                OAK HILL SECURITIES FUND, L.P.
                                By: Oak Hill Securities GenPar II, L.P.,
                                       its General Partner
                                By:  Oak Hill Securities MGP, Inc., its
                                       General Partner


                                By:  /s/ S. Krase
                                     ------------------------------------------
                                Name:  Scott D. Krase
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------


                                OAK HILL SECURITIES FUND II, L.P.
                                By: Oak Hill Securities GenPar II, L.P.,
                                       its General Partner
                                By:  Oak Hill Securities MGP, Inc., its
                                       General Partner


                                By:  /s/ S. Krase
                                     ------------------------------------------
                                Name:  Scott D. Krase
                                       ----------------------------------------
                                Title:  Vice President
                                        ---------------------------------------



                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT



<PAGE>   20



                                STANFIELD/RMF TRANSATLANTIC CDO Ltd.
                                By: Stanfield Capital Partners LLC, as its
                                       Collateral Manager


                                By:  /s/ C.B.
                                     ------------------------------------------
                                Name:  Christopher A. Bondy
                                       ----------------------------------------
                                Title:  Partner
                                        ---------------------------------------



                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT



<PAGE>   21





                                SALOMON BROS. HOLDING


                                By:  /s/ Anila Patel
                                     ------------------------------------------
                                Name:  Anila Patel
                                       ----------------------------------------
                                Title:   Authorized signature
                                       ----------------------------------------





                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   22





                                STEIN ROE & FARNHAM INCORPORATED,
                                       as agent for Keyport Life Insurance
                                       Company


                                By:  /s/ James Fellows
                                     ------------------------------------------
                                Name:    James R. Fellows
                                         --------------------------------------
                                Title:   Sr. Vice President & Portfolio Manager
                                         --------------------------------------



                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT



<PAGE>   23


                   STEIN ROE FLOATING RATE LIMITED
                   LIABILITY COMPANY


                   By:  /s/ Kathleen Zarn
                        -------------------------------------------------------
                   Name:  Kathleen A. Zarn
                          -----------------------------------------------------
                   Title: Vice President, Stein Roe & Farnham Incorporated,
                          -----------------------------------------------------
                          as Advisor to  the Stein Roe Floating Rate
                          -----------------------------------------------------
                          Limited Liability Company
                          -----------------------------------------------------


                   SRF TRADING, INC.


                   By:  /s/ Ann E. Morris
                        -------------------------------------------------------
                   Name:  Ann E. Morris
                          -----------------------------------------------------
                   Title:  Asst. Vice President
                           ----------------------------------------------------




                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT




<PAGE>   24





                                CERES FINANCE LTD.


                                By:  /s/ Joseph Rotondo
                                     ------------------------------------------
                                Name:  Joseph Rotondo
                                       ----------------------------------------
                                Title:  Authorized Officer
                                        ---------------------------------------


                                STRATA FUNDING LTD.


                                By:  /s/ Joseph Rotondo
                                     ------------------------------------------
                                Name:  Joseph Rotondo
                                       ----------------------------------------
                                Title:  Authorized Officer
                                        ---------------------------------------






                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   25





                                TRANSAMERICA BUSINESS CREDIT
                                         CORPORATION


                                By:  /s/ Perry Valvoules
                                     ------------------------------------------
                                Name:  Parry Valvoules
                                       ----------------------------------------
                                Title:  Senior Vice President
                                        ---------------------------------------






                         GAYLORD CONTAINER CORPORATION
                      SECOND AMENDMENT TO CREDIT AGREEMENT


<PAGE>   26






                                    EXHIBIT A


                              OFFICER'S CERTIFICATE


         The undersigned, Thomas M. Steffen, hereby certifies that he is the
duly elected Assistant Treasurer of Gaylord Container Corporation, a Delaware
corporation (the "Borrower"), and pursuant to that certain Second Amendment to
Credit Agreement dated as of August 4, 2000 (the Amendment") by and among the
Borrower, Bankers Trust Company, as Agent, and the financial institutions party
thereto as lenders (capitalized terms used herein shall, unless otherwise
defined herein, have the meaning provided in the Amendment), hereby further
certifies as follows:

         1. No Unmatured Event of Default or Event of Default under the Credit
Agreement (as amended by the Amendment) has occurred and is continuing as of the
date hereof.

         2. After giving effect to the Amendment, the representations and
warranties of the Borrower contained in the Amendment, the Credit Agreement and
the other Loan Documents are true and correct in all material respects as of the
date hereof, with the same effect as though made on such date, except to the
extent that any such representation or warranty relates to an earlier date, in
which case such representation or warranty is true and correct in all material
respects as of such earlier date.

         IN WITNESS WHEREOF, the undersigned has caused this Certificate to
be duly executed and delivered as of August 4, 2000.

                                       GAYLORD CONTAINER CORPORATION




                                       By: /s/ Thomas M. Steffen
                                           ------------------------------------
                                                Thomas M. Steffen
                                                Assistant Treasurer