diff --git a/src/c/interpreter.d b/src/c/interpreter.d
index bef47c055..e3c4c7af0 100644
--- a/src/c/interpreter.d
+++ b/src/c/interpreter.d
@@ -807,14 +807,14 @@ ecl_interpret(cl_object env, cl_object bytecodes, void *pc)
 	CASE(OP_JNIL); {
 		cl_oparg jump = GET_OPARG(vector);
 		NVALUES = 1;
-		if (Null(VALUES(0)))
+		if (Null(reg0))
 			vector += jump - OPARG_SIZE;
 		THREAD_NEXT;
 	}
 	CASE(OP_JT); {
 		cl_oparg jump = GET_OPARG(vector);
 		NVALUES = 1;
-		if (!Null(VALUES(0)))
+		if (!Null(reg0))
 			vector += jump - OPARG_SIZE;
 		THREAD_NEXT;
 	}