diff --git a/libtool-c99.patch b/libtool-c99.patch
new file mode 100644
index 0000000..ffc437a
--- /dev/null
+++ b/libtool-c99.patch
@@ -0,0 +1,20 @@
+Include <string.h> for the strcmp function.  This improves C99
+compiler compatibility because it avoids an implicit function
+declaration.
+
+Submitted upstream:
+
+  <https://lists.gnu.org/archive/html/libtool-patches/2023-01/msg00000.html>
+
+diff --git a/tests/lt_dlopen_a.at b/tests/lt_dlopen_a.at
+index 95f18a0df165d41d..d3948738e4199cc6 100644
+--- a/tests/lt_dlopen_a.at
++++ b/tests/lt_dlopen_a.at
+@@ -27,6 +27,7 @@ AT_KEYWORDS([libltdl lt_dlopen_a])
+ AT_DATA([main.c],
+ [[#include <ltdl.h>
+ #include <stdio.h>
++#include <string.h>
+ 
+ /* This dlopen() in the main executable should override any dlopen()s in
+    shared libraries etc.
diff --git a/libtool.spec b/libtool.spec
index dcc842e..bc2bd07 100644
--- a/libtool.spec
+++ b/libtool.spec
@@ -8,7 +8,7 @@
 Summary: The GNU Portable Library Tool
 Name:    libtool
 Version: 2.4.7
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: GPLv2+ and LGPLv2+ and GFDL
 URL:     http://www.gnu.org/software/libtool/
 
@@ -47,6 +47,8 @@ Patch5: 0001-tests-Fix-grep-warning-about-stray-before.patch
 Patch100: libtool-nodocs.patch
 %endif
 
+Patch101: libtool-c99.patch
+
 # /usr/bin/libtool includes paths within gcc's versioned directories
 # Libtool must be rebuilt whenever a new upstream gcc is built
 # Starting with gcc 7 gcc in Fedora is packaged so that only major
@@ -169,6 +171,9 @@ rm -f %{buildroot}%{_libdir}/libltdl.{a,la}
 
 
 %changelog
+* Tue Jan 10 2023 Florian Weimer <fweimer@redhat.com> - 2.4.7-4
+- C99 compatibility fix in the testsuite
+
 * Wed Dec 21 2022 Frederic Berat <fberat@redhat.com> - 2.4.7-3
 - Fix test failure due to grep update