<PAGE>

                                                              Exhibit 4(b)(viii)


                            FIRST UNION CORPORATION,

                              WACHOVIA CORPORATION

                                       AND

                              THE BANK OF NEW YORK,

                                               as Trustee

                          SECOND SUPPLEMENTAL INDENTURE

                           Dated as of August 31, 2001

                                       to

                                    INDENTURE

                           Dated as of April 23, 1997

                         JUNIOR SUBORDINATED SECURITIES

<PAGE>

     SECOND SUPPLEMENTAL INDENTURE, dated as of August 31, 2001, among FIRST
UNION CORPORATION, a North Carolina corporation ("Successor"), WACHOVIA
CORPORATION, a North Carolina corporation ("Wachovia"), and THE BANK OF NEW
YORK, a New York banking corporation, as trustee (the "Trustee").

     WHEREAS, Central Fidelity Banks, Inc., a Virginia corporation ("Central
Fidelity"), and the Trustee entered into an Indenture, dated as of April 23,
1997, (the "Original Indenture") and Wachovia and the Trustee entered into a
First Supplemental Indenture, dated as of December 15, 1997, (the "First
Supplemental Indenture" and, together with the Original Indenture, the
"Indenture"; capitalized terms not otherwise defined herein shall have the
meanings set forth in the Indenture), providing for the issuance from time to
time of Securities;

     WHEREAS, Wachovia and Successor have entered into an Agreement and Plan of
Merger, dated as of April 15, 2001 (as amended and restated and otherwise
amended or modified, the "Merger Agreement"), which contemplates the execution
and filing of articles of merger (the "Articles of Merger") providing for the
merger of Wachovia with and into Successor (the "Merger"), with Successor
continuing its corporate existence under the laws of the State of North
Carolina;

     WHEREAS, Section 8.01 of the Indenture provides, among other things, that
the Company shall not merge into another corporation unless, among other things,
the corporation into which the Company is merged shall expressly assume, by an
indenture supplemental to the Indenture, executed and delivered to the Trustee,
in form satisfactory to the Trustee, the due and punctual payment of the
principal of and interest (including any Additional Interest) on all the
Securities and the performance of every covenant and every obligation of the
Indenture on the part of the Company to be performed or observed;

     WHEREAS, Section 9.01 of the Indenture provides, among other things, that,
without the consent of any Holders, the Company, when authorized by a Board
Resolution, and the Trustee, at any time and from time to time, may enter into
one or more indentures supplemental to the Indenture, in form satisfactory to
the Trustee, to evidence the succession of another Person to the Company, and
the assumption by any such successor of the covenants of the Company in the
Indenture and in the Securities;

     WHEREAS, Successor and Wachovia desire and have requested that the Trustee
join in the execution of this Second Supplemental Indenture for the purpose of
evidencing such succession and assumption;

     WHEREAS, the execution and delivery of this Second Supplemental Indenture
has been authorized by resolutions of the boards of directors of Wachovia and
Successor; and

     WHEREAS, all conditions precedent and requirements necessary to make this
Second Supplemental Indenture a valid and legally binding instrument in
accordance with its terms have been complied with, performed and fulfilled and
the execution and delivery hereof have been in all respects duly authorized;

<PAGE>

     NOW, THEREFORE, THIS SECOND SUPPLEMENTAL INDENTURE WITNESSETH:

     For and in consideration of the premises and intending to be legally bound
hereby, it is mutually covenanted and agreed, for the equal and proportionate
benefit of all Holders, as follows:

                                  ARTICLE ONE

                    REPRESENTATIONS OF WACHOVIA AND SUCCESSOR

     Each of Wachovia and Successor represents and warrants to the Trustee as
follows:

     SECTION 1.1. It is a corporation duly organized, validly existing and in
good standing under the laws of the State of North Carolina.

     SECTION 1.2. The execution, delivery and performance by it of this Second
Supplemental Indenture have been authorized and approved by all necessary
corporate action on the part of it.

     SECTION 1.3. The Merger will become effective in accordance with the terms
of the Merger Agreement and North Carolina law when the Articles of Merger are
filed in the office of the Secretary of State of the State of North Carolina, or
at such later date or time as the Successor and Wachovia agree and specify in
the Articles of Merger (the time the Merger becomes effective being the
"Effective Time").

     SECTION 1.4. Immediately after giving effect to the Merger, no Event of
Default, and no event which, after notice or lapse of time or both, would become
an Event of Default, shall have happened and be continuing.

                                  ARTICLE TWO

                            ASSUMPTION AND AGREEMENTS

     SECTION 2.1. Successor hereby assumes the due and punctual payment of the
principal of and interest (including any Additional Interest) on all the
Securities and the performance of every covenant and every obligation of the
Indenture on the part of the Company to be performed or observed.

     SECTION 2.2. Securities authenticated and delivered after the execution of
this Second Supplemental Indenture may, and shall if required by the Company,
bear a notation in form approved by the Company as to any matter provided for in
this Second Supplemental Indenture.

     SECTION 2.3. Successor shall succeed to, and be substituted for, and may
exercise every right and power of, the Company under the Indenture, with the
same effect as if Successor had been named as the Company therein, and Wachovia
shall be discharged from all obligations and covenants under the Indenture and
the Securities.

<PAGE>

                                  ARTICLE THREE

                                  MISCELLANEOUS

     SECTION 3.1. The recitals contained herein shall be taken as the statements
of the Company and Successor, and the Trustee assumes no responsibility for
their correctness. The Trustee makes no representations as to the validity or
sufficiency of this Second Supplemental Indenture.

     SECTION 3.2. If any provision of this Second Supplemental Indenture limits,
qualifies or conflicts with the duties imposed by any of Section 310 to 317,
inclusive, of the Trust Indenture Act through operation of 318(c) thereof, such
imposed duties shall control.

     SECTION 3.3. Nothing in this Second Supplemental Indenture, express or
implied, shall give to any Person, other than the parties hereto and their
successors and assigns any benefit or any legal or equitable right, remedy or
claim under this Second Supplemental Indenture.

     SECTION 3.4. This Second Supplemental Indenture shall be governed by and
construed in accordance with the laws of the State of New York, without regard
to principles of conflicts of laws.

     SECTION 3.5. This Second Supplemental Indenture may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original, but all such counterparts shall together constitute but one and the
same instrument.

     SECTION 3.6. This Second Supplemental Indenture shall become effective as
of the Effective Time.

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Second Supplemental
Indenture to be duly executed, and their respective corporate seals to be
hereunto affixed and attested all as of the day and year first above written.

                                        WACHOVIA CORPORATION

                                        By /s/ Kenneth W. McAllister
                                           ----------------------------
                                          Name: Kenneth W. McAllister, Esq.
                                          Title: Senior Executive Vice President
                                                     and General Counsel

(Corporate Seal)

Attest:


 /s/ William Watson
----------------------------
Secretary

                                        FIRST UNION CORPORATION

                                        By /s/ Ross E. Jeffries
                                           ----------------------------
                                          Name:  Ross E. Jeffries
                                          Title: Senior Vice President



(Corporate Seal)

Attest:


/s/ Anthony Augliera
----------------------------
Assistant Secretary

<PAGE>

                                        THE BANK OF NEW YORK, as Trustee



                                        By /s/ Julie Salovitch-Miller
                                          ----------------------------
                                          Name:  Julie Salovitch-Miller
                                          Title: Vice President



(Corporate Seal)

Attest:



/s/ Michael (ILLEGIBLE)
-------------------------

<PAGE>








STATE OF      NORTH CAROLINA         )
         ----------------------------
                                     ):  ss.:
COUNTY OF     FORSYTH                )
         ----------------------------


     On this 31 day of August, 2001, before me, the undersigned officer,
personally appeared Kenneth W. McAllister, who acknowledged himself or herself
to be the Senior Executive Vice President & General Counsel of WACHOVIA
CORPORATION, a North Carolina corporation, and that he or she as such officer,
being authorized to do so, executed the foregoing instrument for the purposes
therein contained by signing the name of the corporation by himself or herself
as such officer.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.


                                        /s/ M. Marie Harper
                                        -------------------------------------
                                        Notary Public

[SEAL]



STATE OF      NORTH CAROLINA         )
          ---------------------------
                                     ):  ss.:
COUNTY OF     MECKLENBURG            )
          ---------------------------



     On this 31 day of August, 2001, before me, the undersigned officer,
personally appeared Ross E. Jeffries, who acknowledged himself or herself to be
the Senior Vice President of FIRST UNION CORPORATION, a North Carolina
corporation, and that he or she as such officer, being authorized to do so,
executed the foregoing instrument for the purposes therein contained by signing
the name of the corporation by himself or herself as such officer.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.


                                        /s/ Loretta M. Lucenti
                                        --------------------------------
                                        Notary Public

[SEAL]

<PAGE>

STATE OF NEW YORK   )
                    ):  ss.:
COUNTY OF NEW YORK  )

     On this 29th day of August, 2001, before me, the undersigned officer,
personally appeared Julie Salovitch-Miller, who acknowledged himself or herself
to be the Vice President of THE BANK OF NEW YORK, a New York banking
corporation, and that he or she as such officer, being authorized to do so,
executed the foregoing instrument for the purposes therein contained by signing
the name of the association by himself or herself as such officer.

     IN WITNESS WHEREOF, I hereunto set my hand and official seal.

                                        /s/ William J. Cassels
                                        --------------------------------
                                        Notary Public

[SEAL]