diff --git a/OpenDreamRuntime/Procs/DMOpcodeHandlers.cs b/OpenDreamRuntime/Procs/DMOpcodeHandlers.cs
index 08e096cf73..146ae1ebf5 100644
--- a/OpenDreamRuntime/Procs/DMOpcodeHandlers.cs
+++ b/OpenDreamRuntime/Procs/DMOpcodeHandlers.cs
@@ -1735,7 +1735,7 @@ public static ProcStatus GetStep(DMProcState state) {
                 return ProcStatus.Continue;
             }
 
-            var dir = d.MustGetValueAsInteger();
+            var dir = d.IsNull ? 0 : d.MustGetValueAsInteger();
 
             state.Push(new(DreamProcNativeHelpers.GetStep(state.Proc.AtomManager, state.Proc.DreamMapManager, loc, (AtomDirection)dir)));
             return ProcStatus.Continue;