diff --git a/cmake-c99.patch b/cmake-c99.patch
new file mode 100644
index 0000000..ce07793
--- /dev/null
+++ b/cmake-c99.patch
@@ -0,0 +1,83 @@
+Improve C compatibility of LoadCommand tests
+
+The previous code used char ** and const char ** types as if they were
+the same. But they are distinct types in C, so when passing these
+pointers as function arguments, their types have to match. Future C
+compilers will treat this as an error, similar to what C++ compilers
+do today.
+
+Submitted upstream:
+
+  <https://gitlab.kitware.com/cmake/cmake/-/merge_requests/9002>
+
+diff --git a/Tests/LoadCommand/CMakeCommands/cmTestCommand.c b/Tests/LoadCommand/CMakeCommands/cmTestCommand.c
+index 7176ebe9d4bd3c4e..ba13727d2b83a051 100644
+--- a/Tests/LoadCommand/CMakeCommands/cmTestCommand.c
++++ b/Tests/LoadCommand/CMakeCommands/cmTestCommand.c
+@@ -16,14 +16,14 @@ static int CCONV InitialPass(void* inf, void* mf, int argc, char* argv[])
+ {
+   char* file;
+   char* str;
+-  char* srcs;
++  const char* srcs;
+   const char* cstr;
+   char buffer[1024];
+   void* source_file;
+   char* args[2];
+-  char* ccArgs[4];
+-  char* ccDep[1];
+-  char* ccOut[1];
++  const char* ccArgs[4];
++  const char* ccDep[1];
++  const char* ccOut[1];
+   cmLoadedCommandInfo* info = (cmLoadedCommandInfo*)inf;
+ 
+   cmVTKWrapTclData* cdata =
+@@ -148,7 +148,10 @@ static int CCONV InitialPass(void* inf, void* mf, int argc, char* argv[])
+   if (info->CAPI->GetTotalArgumentSize(2, args) != 13) {
+     return 0;
+   }
+-  info->CAPI->ExecuteCommand(mf, "SET", 2, args);
++
++  ccArgs[0] = "TEST_EXEC";
++  ccArgs[1] = "TRUE";
++  info->CAPI->ExecuteCommand(mf, "SET", 2, ccArgs);
+ 
+   /* make sure we can find the source file */
+   if (!info->CAPI->GetSource(mf, argv[1])) {
+diff --git a/Tests/LoadCommandOneConfig/CMakeCommands/cmTestCommand.c b/Tests/LoadCommandOneConfig/CMakeCommands/cmTestCommand.c
+index 7176ebe9d4bd3c4e..e3b332c1aa9d9108 100644
+--- a/Tests/LoadCommandOneConfig/CMakeCommands/cmTestCommand.c
++++ b/Tests/LoadCommandOneConfig/CMakeCommands/cmTestCommand.c
+@@ -16,14 +16,14 @@ static int CCONV InitialPass(void* inf, void* mf, int argc, char* argv[])
+ {
+   char* file;
+   char* str;
+-  char* srcs;
+-  const char* cstr;
++  const char* srcs;
++  char* cstr;
+   char buffer[1024];
+   void* source_file;
+   char* args[2];
+-  char* ccArgs[4];
+-  char* ccDep[1];
+-  char* ccOut[1];
++  const char* ccArgs[4];
++  const char* ccDep[1];
++  const char* ccOut[1];
+   cmLoadedCommandInfo* info = (cmLoadedCommandInfo*)inf;
+ 
+   cmVTKWrapTclData* cdata =
+@@ -148,7 +148,10 @@ static int CCONV InitialPass(void* inf, void* mf, int argc, char* argv[])
+   if (info->CAPI->GetTotalArgumentSize(2, args) != 13) {
+     return 0;
+   }
+-  info->CAPI->ExecuteCommand(mf, "SET", 2, args);
++
++  ccArgs[0] = "TEST_EXEC";
++  ccArgs[1] = "TRUE";
++  info->CAPI->ExecuteCommand(mf, "SET", 2, ccArgs);
+ 
+   /* make sure we can find the source file */
+   if (!info->CAPI->GetSource(mf, argv[1])) {
diff --git a/cmake.spec b/cmake.spec
index 61bea0a..dc9618c 100644
--- a/cmake.spec
+++ b/cmake.spec
@@ -72,7 +72,7 @@
 %global patch_version 0
 
 # For handling bump release by rpmdev-bumpspec and mass rebuild
-%global baserelease 1
+%global baserelease 2
 
 # Set to RC version if building RC, else comment out.
 %global rcsuf rc3
@@ -117,6 +117,7 @@ Source5:        %{name}.req
 # http://public.kitware.com/Bug/view.php?id=12965
 # https://bugzilla.redhat.com/show_bug.cgi?id=822796
 Patch100:       %{name}-findruby.patch
+Patch101: cmake-c99.patch
 
 # Patch for renaming on EPEL
 %if 0%{?name_suffix:1}
@@ -549,6 +550,9 @@ popd
 
 
 %changelog
+* Thu Nov 23 2023 Florian Weimer <fweimer@redhat.com> - 3.28.0~rc3-2
+- Improve C compatibility of LoadCommand tests
+
 * Tue Oct 24 2023 Björn Esser <besser82@fedoraproject.org> - 3.28.0~rc3-1
 - cmake-3.28.0-rc3
   Fixes rhbz#2243343