diff --git a/public/xash3d_mathlib.h b/public/xash3d_mathlib.h
index a8f2a8a460..c0d49edd66 100644
--- a/public/xash3d_mathlib.h
+++ b/public/xash3d_mathlib.h
@@ -20,6 +20,7 @@ GNU General Public License for more details.
 #if HAVE_TGMATH_H
 #include <tgmath.h>
 #endif
+#include <string.h>
 
 #include "build.h"
 #include "xash3d_types.h"