diff --git a/indra/aistatemachine/aicondition.cpp b/indra/aistatemachine/aicondition.cpp
index fa35104a8..2c9a4f8e8 100644
--- a/indra/aistatemachine/aicondition.cpp
+++ b/indra/aistatemachine/aicondition.cpp
@@ -28,6 +28,7 @@
  *   Initial version, written by Aleric Inglewood @ SL
  */
 
+#include "sys.h"
 #include "aicondition.h"
 #include "aistatemachine.h"