diff --git a/lib/CodeGen/ScheduleDAGInstrs.h b/lib/CodeGen/ScheduleDAGInstrs.h
index 1a9d1ea5789..c7ffed96b78 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.h
+++ b/lib/CodeGen/ScheduleDAGInstrs.h
@@ -152,7 +152,7 @@ namespace llvm {
       /// Otherwise map the register and return an empty SUnits vector.
       std::vector<SUnit *> &operator[](unsigned Reg) {
         bool New = PhysRegSet.insert(Reg).second;
-        assert(!New || SUnits[Reg].empty() && "stale SUnits vector");
+        assert((!New || SUnits[Reg].empty()) && "stale SUnits vector");
         (void)New;
         return SUnits[Reg];
       }