diff --git a/lib/Target/ARM/Thumb2InstrInfo.cpp b/lib/Target/ARM/Thumb2InstrInfo.cpp
index 836c1baffd4..9b1073be3c8 100644
--- a/lib/Target/ARM/Thumb2InstrInfo.cpp
+++ b/lib/Target/ARM/Thumb2InstrInfo.cpp
@@ -95,8 +95,11 @@ Thumb2InstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
 bool
 Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MBBI) const {
-  while (MBBI->isDebugValue())
+  while (MBBI->isDebugValue()) {
     ++MBBI;
+    if (MBBI == MBB.end())
+      return false;
+  }
 
   unsigned PredReg = 0;
   return llvm::getITInstrPredicate(MBBI, PredReg) == ARMCC::AL;