diff --git a/plugins/include/amxconst.inc b/plugins/include/amxconst.inc
index ec53900b..29ac69b0 100755
--- a/plugins/include/amxconst.inc
+++ b/plugins/include/amxconst.inc
@@ -15,7 +15,7 @@
 #define AMXX_VERSION_NUM	175
 stock const AMXX_VERSION_STR[]="1.75"
 
-#define PI 3.1415926535
+#define M_PI 3.1415926535
 
 #define ADMIN_ALL		0	/* everyone */
 #define ADMIN_IMMUNITY		(1<<0)	/* flag "a" */