diff --git a/source/blender/blenkernel/intern/navmesh_conversion.cpp b/source/blender/blenkernel/intern/navmesh_conversion.cpp
index 245a2b23091..cc3b926db75 100644
--- a/source/blender/blenkernel/intern/navmesh_conversion.cpp
+++ b/source/blender/blenkernel/intern/navmesh_conversion.cpp
@@ -28,6 +28,7 @@
 */
 
 #include <math.h>
+#include <stdlib.h>
 #include "Recast.h"
 
 extern "C"{