diff --git a/mutt-configure-c99.patch b/mutt-configure-c99.patch
new file mode 100644
index 0000000..0ea7010
--- /dev/null
+++ b/mutt-configure-c99.patch
@@ -0,0 +1,24 @@
+The standard iconv function uses char ** even for its input
+argument. With a const char ** argument, ICONV_NONTRANS is incorrectly
+set to 1 if the compiler produces an error for such incompatible
+pointer types.
+
+Submitted upstream: <https://gitlab.com/muttmua/mutt/-/merge_requests/175>
+
+diff --git a/configure.ac b/configure.ac
+index 9fe461df2a5af3a8..443da363081343c5 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -1322,10 +1322,10 @@ AC_CACHE_CHECK([whether iconv is non-transcribing], mutt_cv_iconv_nontrans,
+ int main()
+ {
+   iconv_t cd;
+-  const char *ib;
++  char *ib;
+   char *ob;
+   size_t ibl, obl;
+-  const char *s = "\304\211";
++  char *s = (char *) "\304\211";
+ changequote(, )dnl
+   char t[3];
+ changequote([, ])dnl
diff --git a/mutt.spec b/mutt.spec
index 6e0a258..7b50be4 100644
--- a/mutt.spec
+++ b/mutt.spec
@@ -20,7 +20,7 @@
 Summary: A text mode mail user agent
 Name: mutt
 Version: 2.2.12
-Release: 1%{?dist}
+Release: 2%{?dist}
 Epoch: 5
 # The entire source code is GPLv2+ except
 # pgpewrap.c setenv.c sha1.c wcwidth.c which are Public Domain
@@ -38,6 +38,7 @@ Patch9: mutt-1.9.0-ssl_ciphers.patch
 Patch10: mutt-1.9.4-lynx_no_backscapes.patch
 Patch12: mutt-1.9.5-nodotlock.patch
 Patch13: mutt-1.12.1-optusegpgagent.patch
+Patch14: mutt-configure-c99.patch
 
 Url: http://www.mutt.org
 Requires: mailcap, urlview
@@ -86,6 +87,7 @@ for selecting groups of messages.
 
 %patch10 -p1 -b .lynx_no_backscapes
 %patch12 -p1 -b .nodotlock
+%patch14 -p1
 
 autoreconf --install
 %patch1 -p1 -b .muttrc
@@ -218,6 +220,9 @@ ln -sf ./muttrc.5 %{buildroot}%{_mandir}/man5/muttrc.local.5
 
 
 %changelog
+* Thu Dec  7 2023 Florian Weimer <fweimer@redhat.com> - 5:2.2.12-2
+- Fix C99 compatibility issue
+
 * Mon Nov 13 2023 Matej Mužila <mmuzila@redhat.com> - 5:2.2.12-1
 - Upgrade to 2.2.12
 - Resolves: #2232712