diff --git a/src/thingdef/thingdef_expression.cpp b/src/thingdef/thingdef_expression.cpp
index f68ba4ec2b..f4c2b1f608 100644
--- a/src/thingdef/thingdef_expression.cpp
+++ b/src/thingdef/thingdef_expression.cpp
@@ -1697,7 +1697,7 @@ ExpEmit FxBinaryLogical::Emit(VMFunctionBuilder *build)
 	else
 	{
 		assert(Operator == TK_OrOr);
-		build->Emit(OP_EQ_K, 1, op1.RegNum, zero);
+		build->Emit(OP_EQ_K, 0, op1.RegNum, zero);
 		// If op1 is not 0, skip evaluation of op2.
 		size_t patchspot = build->Emit(OP_JMP, 0, 0, 0);