diff --git a/wadsrc/static/zscript/base.txt b/wadsrc/static/zscript/base.txt
index d8cae2ec9..a3ca6fdb9 100644
--- a/wadsrc/static/zscript/base.txt
+++ b/wadsrc/static/zscript/base.txt
@@ -364,7 +364,7 @@ class BlockLinesIterator : Object native
 	native int portalflags;
 	
 	native static BlockThingsIterator Create(Actor origin, double checkradius = -1);
-	native static BlockThingsIterator CreateFromPos(Vector3 pos, double checkh, double checkradius, Sector sec = nullptr;
+	native static BlockThingsIterator CreateFromPos(Vector3 pos, double checkh, double checkradius, Sector sec = null);
 	native bool Next();
 }