diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index ea22edbf4..01fa8a2a2 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -329,7 +329,7 @@ ACTOR Actor native //: Thinker
 	native state A_CheckSightOrRange(float distance, state label, bool two_dimension = false);
 	native state A_CheckRange(float distance, state label, bool two_dimension = false);
 	action native bool A_FaceMovementDirection(float offset = 0, float anglelimit = 0, float pitchlimit = 0, int flags = 0, int ptr = AAPTR_DEFAULT);
-	action native int A_ClearOverlays(int start = 0, int stop = 0, bool safety = true);
+	action native int A_ClearOverlays(int sstart = 0, int sstop = 0, bool safety = true);
 
 	native void A_RearrangePointers(int newtarget, int newmaster = AAPTR_DEFAULT, int newtracer = AAPTR_DEFAULT, int flags=0);
 	native void A_TransferPointer(int ptr_source, int ptr_recepient, int sourcefield, int recepientfield=AAPTR_DEFAULT, int flags=0);