diff --git a/src/gallium/auxiliary/util/u_format_rgb9e5.h b/src/gallium/auxiliary/util/u_format_rgb9e5.h
index 9e4b1d607d7..59fc291e917 100644
--- a/src/gallium/auxiliary/util/u_format_rgb9e5.h
+++ b/src/gallium/auxiliary/util/u_format_rgb9e5.h
@@ -26,9 +26,10 @@
 #ifndef RGB9E5_H
 #define RGB9E5_H
 
-#include <math.h>
 #include <assert.h>
 
+#include "c99_math.h"
+
 #define RGB9E5_EXPONENT_BITS          5
 #define RGB9E5_MANTISSA_BITS          9
 #define RGB9E5_EXP_BIAS               15