diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index ae9223319..9c86e43e6 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -660,7 +660,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_JumpIfTargetInsideMeleeRange)
 //==========================================================================
 void DoJumpIfCloser(AActor *target, DECLARE_PARAMINFO)
 {
-	ACTION_PARAM_START(2);
+	ACTION_PARAM_START(3);
 	ACTION_PARAM_FIXED(dist, 0);
 	ACTION_PARAM_STATE(jump, 1);
 	ACTION_PARAM_BOOL(noz, 2);