diff --git a/src/ExtMath.c b/src/ExtMath.c
index a44587c45..61eb279fc 100644
--- a/src/ExtMath.c
+++ b/src/ExtMath.c
@@ -5,6 +5,7 @@
 #include <stdlib.h>
 
 #ifndef __GNUC__
+#include <math.h>
 float Math_AbsF(float x)  { return fabsf(x); /* MSVC intrinsic */ }
 float Math_SqrtF(float x) { return sqrtf(x); /* MSVC intrinsic */ }
 #endif