diff --git a/source/blender/editors/space_outliner/outliner_select.c b/source/blender/editors/space_outliner/outliner_select.c
index f43e9b19672..c06576e48a6 100644
--- a/source/blender/editors/space_outliner/outliner_select.c
+++ b/source/blender/editors/space_outliner/outliner_select.c
@@ -29,6 +29,8 @@
  *  \ingroup spoutliner
  */
 
+#include <stdlib.h>
+
 #include "MEM_guardedalloc.h"
 
 #include "DNA_armature_types.h"