diff --git a/lpsolve-ccc-c99.patch b/lpsolve-ccc-c99.patch
new file mode 100644
index 0000000..929138b
--- /dev/null
+++ b/lpsolve-ccc-c99.patch
@@ -0,0 +1,51 @@
+Port the ccc build configuration detection tool to C99 by
+specifying the return type of main as int.
+
+Submitted upstream:
+
+  <https://groups.google.com/g/lp_solve/c/WjVf0dxrwfQ/m/rKMwf57tAwAJ>
+
+diff --git a/lp_solve/ccc b/lp_solve/ccc
+index 9b79cea7ee71536c..b1f761aab33345d4 100644
+--- a/lp_solve/ccc
++++ b/lp_solve/ccc
+@@ -6,7 +6,7 @@ c=$CC
+ >/tmp/platform.c
+ echo '#include <stdlib.h>'>>/tmp/platform.c
+ echo '#include <stdio.h>'>>/tmp/platform.c
+-echo 'main(){printf("ux%d", (int) (sizeof(void *)*8));}'>>/tmp/platform.c
++echo 'int main(){printf("ux%d", (int) (sizeof(void *)*8));}'>>/tmp/platform.c
+ $c /tmp/platform.c -o /tmp/platform
+ PLATFORM=`/tmp/platform`
+ rm /tmp/platform /tmp/platform.c >/dev/null 2>&1
+@@ -20,7 +20,7 @@ math=-lm
+ echo '#include <stdio.h>'>>/tmp/isnan.c
+ echo '#include <stdlib.h>'>>/tmp/isnan.c
+ echo '#include <math.h>'>>/tmp/isnan.c
+-echo 'main(){isnan(0.0);}'>>/tmp/isnan.c
++echo 'int main(){isnan(0.0);}'>>/tmp/isnan.c
+ $c /tmp/isnan.c -o /tmp/isnan $math >/dev/null 2>&1
+ if [ $? = 0 ]
+ then NOISNAN=
+diff --git a/lpsolve55/ccc b/lpsolve55/ccc
+index 0470611bc45a851c..ca350f257add7730 100644
+--- a/lpsolve55/ccc
++++ b/lpsolve55/ccc
+@@ -6,7 +6,7 @@ c=$CC
+ >/tmp/platform.c
+ echo '#include <stdlib.h>'>>/tmp/platform.c
+ echo '#include <stdio.h>'>>/tmp/platform.c
+-echo 'main(){printf("ux%d", (int) (sizeof(void *)*8));}'>>/tmp/platform.c
++echo 'int main(){printf("ux%d", (int) (sizeof(void *)*8));}'>>/tmp/platform.c
+ $c /tmp/platform.c -o /tmp/platform
+ PLATFORM=`/tmp/platform`
+ rm /tmp/platform /tmp/platform.c >/dev/null 2>&1
+@@ -18,7 +18,7 @@ mkdir bin bin/$PLATFORM >/dev/null 2>&1
+ echo '#include <stdio.h>'>>/tmp/isnan.c
+ echo '#include <stdlib.h>'>>/tmp/isnan.c
+ echo '#include <math.h>'>>/tmp/isnan.c
+-echo 'main(){isnan(0.0);}'>>/tmp/isnan.c
++echo 'int main(){isnan(0.0);}'>>/tmp/isnan.c
+ $c /tmp/isnan.c -o /tmp/isnan $math >/dev/null 2>&1
+ if [ $? = 0 ]
+ then NOISNAN=
diff --git a/lpsolve.spec b/lpsolve.spec
index 4d8bf36..1ade7a2 100644
--- a/lpsolve.spec
+++ b/lpsolve.spec
@@ -1,7 +1,7 @@
 Name:      lpsolve
 Summary:   A Mixed Integer Linear Programming (MILP) solver
 Version:   5.5.2.0
-Release:   29%{?dist}
+Release:   30%{?dist}
 Source:    http://downloads.sourceforge.net/lpsolve/lp_solve_%{version}_source.tar.gz
 URL:       http://sourceforge.net/projects/lpsolve
 License:   LGPLv2+
@@ -11,6 +11,7 @@ BuildRequires: gcc-c++
 Patch0:    lpsolve-5.5.0.11.cflags.patch
 Patch1:    lpsolve-5.5.2.0.defines.patch
 Patch2:    read-cc-from-env.patch
+Patch3:    lpsolve-ccc-c99.patch
 
 %description
 Mixed Integer Linear Programming (MILP) solver lpsolve solves pure linear,
@@ -28,6 +29,7 @@ Includes and definitions for developing with lpsolve
 %patch0 -p1 -b .cflags.patch
 %patch1 -p1 -b .defines.patch
 %patch2 -p1 -b .cc-from-env.patch
+%patch3 -p1 -b .ccc-c99.patch
 
 %build
 %set_build_flags
@@ -58,6 +60,9 @@ install -p -m 644 \
 %{_includedir}/lpsolve
 
 %changelog
+* Fri Nov 25 2022 Florian Weimer <fweimer@redhat.com> - 5.5.2.0-30
+- Port the ccc build configuration tool to C99
+
 * Thu Jul 21 2022 Fedora Release Engineering <releng@fedoraproject.org> - 5.5.2.0-29
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild