diff --git a/CMake/CurlTests.c b/CMake/CurlTests.c
index 848e0d5d79..f7290c3981 100644
--- a/CMake/CurlTests.c
+++ b/CMake/CurlTests.c
@@ -607,7 +607,9 @@ int fun2(int arg1, int arg2) {
 int
 main() {
   int res3 = gcc_vmacro3(1, 2, 3);
+  (void)res3;
   int res2 = gcc_vmacro2(1, 2);
+  (void)res2;
   return 0;
 }
 #endif