diff --git a/source/blender/blenkernel/intern/group.c b/source/blender/blenkernel/intern/group.c
index 2a4d3f6d301..c8848572643 100644
--- a/source/blender/blenkernel/intern/group.c
+++ b/source/blender/blenkernel/intern/group.c
@@ -29,6 +29,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <math.h>
 
 #include "MEM_guardedalloc.h"