diff --git a/source/blender/freestyle/intern/system/BaseObject.h b/source/blender/freestyle/intern/system/BaseObject.h
index 1c5c9b967b9..a6731c74cb9 100644
--- a/source/blender/freestyle/intern/system/BaseObject.h
+++ b/source/blender/freestyle/intern/system/BaseObject.h
@@ -14,6 +14,8 @@
 #  include "MEM_guardedalloc.h"
 #endif
 
+#include "BLI_sys_types.h"
+
 namespace Freestyle {
 
 class BaseObject {
diff --git a/source/blender/freestyle/intern/system/TimeStamp.h b/source/blender/freestyle/intern/system/TimeStamp.h
index 2edda08c738..eaaf68907e7 100644
--- a/source/blender/freestyle/intern/system/TimeStamp.h
+++ b/source/blender/freestyle/intern/system/TimeStamp.h
@@ -13,6 +13,8 @@
 #  include "MEM_guardedalloc.h"
 #endif
 
+#include "BLI_sys_types.h"
+
 namespace Freestyle {
 
 class TimeStamp {