diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index bcff1f6f6ab..34cebaed240 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -825,7 +825,7 @@ void ScheduleDAGInstrs::insertBarrierChain(Value2SUsMap &map) {
     }
 
     // Remove also the BarrierChain from list if present.
-    if (*SUItr == BarrierChain)
+    if (SUItr != SUEE && *SUItr == BarrierChain)
       SUItr++;
 
     // Remove all SUs that are now successors of BarrierChain.