diff --git a/sc2/src/uqm/flash.c b/sc2/src/uqm/flash.c
index 9afbd2d66..cfaa3a14a 100644
--- a/sc2/src/uqm/flash.c
+++ b/sc2/src/uqm/flash.c
@@ -453,7 +453,7 @@ Flash_getRect (FlashContext *context, RECT *rect)
 void
 Flash_setOverlay (FlashContext *context, const POINT *origin,
 		FRAME overlay) {
-	assert(context->type = FlashType_overlay);
+	assert(context->type == FlashType_overlay);
 
 	if (context->started)
 	{