diff --git a/test/core/core_setup_force_cxx98.cpp b/test/core/core_setup_force_cxx98.cpp
index 4b59501a..32bb63c3 100644
--- a/test/core/core_setup_force_cxx98.cpp
+++ b/test/core/core_setup_force_cxx98.cpp
@@ -1,4 +1,6 @@
-#define GLM_FORCE_CXX98
+#ifndef GLM_FORCE_CXX98
+#	define GLM_FORCE_CXX98
+#endif
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>