diff --git a/test/core/core_force_arch_unknown.cpp b/test/core/core_force_arch_unknown.cpp
index b8072ccd..45b51bf0 100644
--- a/test/core/core_force_arch_unknown.cpp
+++ b/test/core/core_force_arch_unknown.cpp
@@ -1,4 +1,6 @@
-#define GLM_FORCE_ARCH_UNKNOWN
+#ifndef GLM_FORCE_ARCH_UNKNOWN
+#	define GLM_FORCE_ARCH_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>
diff --git a/test/core/core_force_compiler_unknown.cpp b/test/core/core_force_compiler_unknown.cpp
index ca6f0e1e..44d7fc33 100644
--- a/test/core/core_force_compiler_unknown.cpp
+++ b/test/core/core_force_compiler_unknown.cpp
@@ -1,4 +1,6 @@
-#define GLM_FORCE_COMPILER_UNKNOWN
+#ifndef GLM_FORCE_COMPILER_UNKNOWN
+#	define GLM_FORCE_COMPILER_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>
diff --git a/test/core/core_force_platform_unknown.cpp b/test/core/core_force_platform_unknown.cpp
index 65110ad7..fb7fa757 100644
--- a/test/core/core_force_platform_unknown.cpp
+++ b/test/core/core_force_platform_unknown.cpp
@@ -1,4 +1,6 @@
-#define GLM_FORCE_PLATFORM_UNKNOWN
+#ifndef GLM_FORCE_PLATFORM_UNKNOWN
+#	define GLM_FORCE_PLATFORM_UNKNOWN
+#endif
 
 #include <glm/glm.hpp>
 #include <glm/ext.hpp>