<PAGE>

                                                                 Exhibit 10.5(f)



              AMENDMENT NO. 5, WAIVER AND AGREEMENT dated as of March 28, 2001
         (this "Amendment"), to the Amended and Restated Credit Agreement dated
         as of November 18, 1998, as amended (the "Credit Agreement"), among
         Jefferson Smurfit Corporation (U.S.), a Delaware corporation (the
         "Borrower"); Smurfit-Stone Container Corporation, a Delaware
         corporation ("SSCC"); JSCE, Inc., a Delaware corporation ("JSCE"); the
         lenders party thereto from time to time (the "Lenders"); the Managing
         Agents and Fronting Banks named therein; Bankers Trust Company, a New
         York banking corporation and The Chase Manhattan Bank, a New York
         banking corporation ("Chase"), as senior managing agents (in such
         capacity, the "Senior Managing Agents") for the Lenders; and Chase, as
         swingline lender (in such capacity, the "Swingline Lender"), as
         administrative agent (in such capacity, the "Administrative Agent") and
         as collateral agent (in such capacity, the "Collateral Agent").


     A.  Pursuant to the terms and subject to the conditions contained in the
Credit Agreement, the Lenders, the Swingline Lender and the Fronting Banks have
extended, and have agreed to extend, credit to the Borrower.

     B.  The Borrower has informed the Administrative Agent that it expects to
have Excess Cash Flow for the year ended December 31, 2000, of approximately
$118,000,000.  Pursuant to Section 2.13(c) of the Credit Agreement, on or around
March 31, 2001, the Borrower would be required to prepay the Term Loans by an
amount equal to 50% of such Excess Cash Flow (the "2000 Excess Cash Flow
Prepayment").

     C.  The Borrower has also informed the Administrative Agent that it intends
to call for redemption all the 10-Year Senior Notes in an aggregate outstanding
principal amount of approximately $287,000,000, and to redeem such notes on or
about May 1, 2001 (the "Redemption").



                                       1
<PAGE>

     D.  The Borrower intends to finance the Redemption and to pay related fees
and expenses with a combination of (i) the proceeds of the Additional Term
Facilities (as defined in Section 1 below) and (ii) cash that would otherwise be
required to be used to make the 2000 Excess Cash Flow Prepayment.

     E.  SSCC and the Borrower have requested that the Required Lenders (i)
agree to amend the Credit Agreement to allow for the provision of the Additional
Term Facilities thereunder and (ii) waive compliance by the Borrower with (a)
Section 2.13(c) of the Credit Agreement with respect to the 2000 Excess Cash
Flow Prepayment and (b) Section 7.09(a) of the Credit Agreement to the extent
necessary to permit the Redemption.

     F.  The Required Lenders are willing so to amend the Credit Agreement and
to grant such waivers on the terms and subject to the conditions herein
contained.

     G.  Capitalized terms used but not otherwise defined herein shall have the
meanings assigned to them in the Credit Agreement.

     Accordingly, in consideration of the mutual agreements herein contained and
other good and valuable consideration, the sufficiency and receipt of which are
hereby acknowledged, the parties hereto agree as follows:

     SECTION 1.  Amendment.  The following is hereby inserted as a new section
following Section 10.20 of the Credit Agreement:

     "SECTION 10.21. Additional Term Facilities. (a) The Borrower may, by
   written notice to the Administrative Agent, request that one or more Lenders,
   banks, financial institutions or other entities (collectively, the
   "Additional Term Lenders") agree to make term loans in one or more tranches
   and in an aggregate principal amount not to exceed $275,000,000 (the
   "Additional Term Loans") to the Borrower pursuant to a supplement hereto or
   an amendment hereof in form and substance satisfactory to the Borrower, the
   Administrative Agent and the Additional Term Lenders; provided, however, that
   the proceeds of any such Additional Term Loans shall be used by the Borrower
   solely to redeem the 10-Year Senior Notes and to pay related fees and
   expenses.

     (b)  The Required Lenders hereby authorize the Administrative Agent on
   behalf of the Required Lenders


                                       2
<PAGE>

   to enter into any amendment (including an amendment and restatement) of this
   Agreement solely to the extent necessary to reflect the making of the
   Additional Term Loans (or the commitment to make the same) on the terms
   described in this Section 10.21; provided, however, that, without the further
   consent of the Required Lenders, the final maturity and the weighted average
   life of the Additional Term Loans shall not be shorter than the final
   maturity and the weighted average life of the outstanding Term Loans. The
   Administrative Agent shall promptly deliver copies of any such amendment to
   the Lenders.

     (c) It is the intent of the parties hereto that the Additional Term Loans
   (when and if made) shall constitute Loans and Obligations, and that the
   Additional Term Lenders shall constitute Lenders and Secured Parties,
   hereunder and under the other Loan Documents. Accordingly, the Additional
   Term Loans shall rank pari passu in right of payment to, and shall be secured
   equally and ratably with, the other Loans and Obligations outstanding under
   this Agreement and the other Loan Documents."

     SECTION 2. Waivers.  (a)  The Required Lenders hereby waive compliance by
the Borrower with Section 2.13(c) of the Credit Agreement with respect to the
2000 Excess Cash Flow Prepayment; provided, however, that the waiver contained
in this Section 2(a) shall cease to be effective on June 5, 2001, and the 2000
Excess Cash Flow Prepayment shall be required to be made on such date, if the
Redemption shall not have occurred on or prior to such date.

     (b)  The Required Lenders hereby waive compliance by the Borrower with
Section 7.09(a) of the Credit Agreement to the extent (but only to the extent)
necessary to permit the Redemption.

     SECTION 3.  Agreement.  SSCC, the Borrower, JSCE and the Required Lenders
hereby agree that, notwithstanding anything to the contrary contained herein or
in the Credit Agreement, the amount of the 2000 Excess Cash Flow Prepayment
(whether or not made) shall not be included in the calculation of the Borrower's
Portion of Excess Cash Flow.

     SECTION 4.  Representations and Warranties.  To induce the other parties
hereto to enter into this Amendment, each of SSCC, the Borrower and JSCE
represents and warrants to each of the Lenders, the Administrative



                                       3
<PAGE>

Agent, the Senior Managing Agents, the Managing Agents, the Fronting Banks, the
Swingline Lender and the Collateral Agent that, after giving effect to this
Waiver, (a) the representations and warranties set forth in Article IV of the
Credit Agreement are true and correct in all material respects on and as of the
date hereof, except to the extent such representations and warranties expressly
relate to an earlier date and (b) no Default or Event of Default has occurred
and is continuing.

     SECTION 5.  Conditions to Effectiveness.  This Amendment shall become
effective on the date on which the Administrative Agent shall have received
counterparts of this Amendment that, when taken together, bear the signatures of
SSCC, JSCE, the Borrower and the Required Lenders.

     SECTION 6.  Effect of Amendment.  Except as expressly set forth herein,
this Amendment shall not by implication or otherwise limit, impair, constitute a
waiver of, or otherwise affect the rights and remedies of the Lenders, the
Fronting Banks, the Swingline Lender, the Collateral Agent, the Administrative
Agent, the Senior Managing Agents, the Managing Agents, SSCC, JSCE, the Borrower
or the Guarantors under the Credit Agreement or any other Loan Document, and
shall not alter, modify, amend or in any way affect any of the terms,
conditions, obligations, covenants or agreements contained in the Credit
Agreement or any other Loan Document, all of which are ratified and affirmed in
all respects and shall continue in full force and effect.  Nothing herein shall
be deemed to entitle SSCC, JSCE, the Borrower or the Guarantors to a consent to,
or a waiver, amendment, modification or other change of, any of the terms,
conditions, obligations, covenants or agreements contained in the Credit
Agreement or any other Loan Document in similar or different circumstances.

     SECTION 7.  Counterparts.  This Amendment may be executed in any number of
counterparts and by different parties hereto in separate counterparts, each of
which when so executed and delivered shall be deemed an original, but all such
counterparts constitute but one and the same instrument.  Delivery of any
executed counterpart of a signature page of this Amendment by facsimile
transmission shall be effective as delivery of a manually executed counterpart
hereof.

     SECTION 8.  APPLICABLE LAW.  THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.



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<PAGE>

     SECTION 9.  Headings.  The headings of this Amendment are for purposes of
reference only and shall not limit or otherwise affect the meaning hereof.



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<PAGE>

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



                   JEFFERSON SMURFIT CORPORATION (U.S.),


                   by /s/  Richard P. Marra
                   ------------------------
                    Name:  Richard P. Marra
                    Title: Assistant Treasurer


                   SMURFIT-STONE CORPORATION,

                    by /s/  Richard P. Marra
                    ------------------------
                    Name:  Richard P. Marra
                    Title: Assistant Treasurer


                   JSCE, INC.,

                    by /s/  Richard P. Marra
                    ------------------------
                    Name:  Richard P. Marra
                    Title: Assistant Treasurer


                   THE CHASE MANHATTAN BANK, individually and as Administrative
                   Agent, Collateral Agent and Senior Managing Agent,

                    by /s/  Peter S. Predun
                    -----------------------
                    Name:  Peter S. Predun
                    Title: Vice President


                   BANKERS TRUST COMPANY, individually and as Fronting Bank and
                   Senior Managing Agent,

                    by /s/  Robert R. Telesca
                    -------------------------
                    Name:  Robert R. Telesca
                    Title: Assistant Vice President



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<PAGE>

                  APEX (IDM) CDOI, LTD.

                   by /s/ Glenn Duffy
                   ------------------
                   Name:  Glenn Duffy
                   Title: Director


                  BANK OF AMERICA, N.A.

                   by /s/ Michael Balok
                   --------------------
                   Name:  Michael Balok
                   Title: Managing Director


                  THE BANK OF NEW YORK

                   by /s/ David G. Shedd
                   ---------------------
                   Name:  David G. Shedd
                   Title: Vice President


                  THE BANK OF NOVA SCOTIA

                   by /s/ F. C. H. Askby
                   ---------------------
                   Name:  F. C. H. Askby
                   Title: Senior Manager Loan
                          Operations


                  BANK TRUST COMPANY

                   by /s/ Robert R. Telesca
                   ------------------------
                   Name:  Robert R. Telesca
                   Title: Assistant Vice
                          President



                                       7
<PAGE>

                  CREDIT INDUSTRIEL ET COMMERCIAL

                   by /s/ Sean Mounier
                   -------------------
                   Name:  Sean Mounier
                   Title: First Vice President

                   by /s/ Marcus Edward
                   --------------------
                   Name:  Sean Mounier
                   Title: Vice President


                  EATION VANCE CDO III, LTD.

                   by EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR

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


                  EATION VANCE SENIOR INCOME TRUST

                   by EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR

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


                  EATION VANCE INSTITUTIONAL SENIOR LOAN FUND

                   by EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR

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


                  FIRST UNION NATIONAL BANK

                   by /s/ Andrew Phelps
                   --------------------
                   Name:  Andrew Phelps
                   Title: Vice President



                                       8
<PAGE>

                  FORTIS CAPITAL CORP.

                   by /s/ John C. Preneta
                   ----------------------
                   Name:  John C. Preneta
                   Title: Executive Vice President

                   by /s/ Eugene Oliva
                   -------------------
                   Name:  Eugene Oliva
                   Title: Vice President


                  GRAYSON & CO.

                   by BOSTON MANAGEMENT AND RESEARCH AS INVESTMENT ADVISOR

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


                  GRAYSTON CLO 2001-1 LTD

                   by BEAR STEARNS ASSET
                      MANAGEMENT INC., as its
                      Collateral Manager

                   by /s/ Niell D. Rosenberg
                   -------------------------
                   Name:  Niell D. Rosenberg
                   Title: Vice President


                  THE INDUSTRIAL BANK OF JAPAN, LTD.

                   by /s/ J. Kenneth Biegen
                   ------------------------
                   Name:  J. Kenneth Biegen
                   Title: Senior Vice President


                  KZH CRESCENT LLC

                   by /s/ Kimberly Rowe
                   --------------------
                   Name:  Kimberly Rowe
                   Title: Authorized Agent



                                       9
<PAGE>

                  MERRILL LYNCH GLOBAL INVESTMENT SERIES:
                  INCOME STRATEGIES PORTFOLIO

                  by MERRILL LYNCH INVESTMENT
                  MANAGERS, L.P., as Investment Advisor

                   by /s/ Jaimin Patel
                   -------------------
                   Name:  Jaimin Patel
                   Title: Authorized Signatory


                  NORTHWOODS CAPITAL, LIMITED

                   by ANGELO, GORDON & CO., L.P.,
                      as Collateral Manager

                   by /s/ John W. Fraser
                   ---------------------
                   Name:  John W. Fraser
                   Title: Managing Director

                  OXFORD STRATEGIC INCOME FUND

                   by EATON VANCE MANAGMENT AS  INVESTMENT ADVISOR

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


                  THE PRUDENTIAL INSURANCE COMPANY
                  OF AMERICA

                   by /s/ Brian Smead
                   ------------------
                   Name:  Brian Smead
                   Title:
                  SENIOR DEBT PORTFOLIO

                   by BOSTON MANAGEMENT & RESEARCH AS INVESTMENT ADVISOR

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



                                       10
<PAGE>

                  SEQUILS I, LTD

                   by TCW ADVISORS, INC., as it
                      Collateral Manager

                   by /s/ Mark Gold
                   ----------------
                   Name:  Mark Gold
                   Title: Managing Director

                   by /s/ Jonathan R. Insull
                   -------------------------
                   Name:  Jonathan R. Insull
                   Title: Senior Vice President


                  SRF TRADING, INC.

                   by /s/ Ann E. Morris
                   --------------------
                   Name:  Ann E. Morris
                   Title: Assistant Vice
                          President


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

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



                                       11
<PAGE>

                  TCW LEVERAGED INCOME TRUST IV, L.P.

                   by TCW (LINC IV), L.L.C., as
                                General Partner

                   by TCW ASSET MANAGEMENT COMPANY, as managing member of the
                  General Partner

                   by /s/ Marc L. Gold
                   -------------------
                   Name:  Marc L. Gold
                   Title: Managing Director


                   by /s/ Jonathan R. Insull
                   -------------------------
                   Name:  Jonathan R. Insull
                   Title: Senior Vice President


                  TRYON CLO LTD. 2000-1

                   by /s/ Glenn Duffy
                   ------------------
                   Name:  Glenn Duffy
                   Title: Director


                  UNITED OF OMAHA LIFE INSURANCE COMPANY

                   by TCW ASSET MANAGEMENT COMPANY, as its Investment Advisor

                   by /s/ Marc L. Gold
                   -------------------
                   Name:  Marc L. Gold
                   Title: Managing Director

                   by /s/ Jonathan R. Insull
                   -------------------------
                   Name:  Jonathan R. Insull
                   Title: Senior Vice President


                  WINGED FOOT FUNDING TRUST

                   by /s/ Ann E. Morris
                   --------------------
                   Name:  Ann E. Morris
                   Title: Authorized Agent



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