diff --git a/include/llvm/CodeGen/MachineBlockFrequencyInfo.h b/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
index 0f8d69ebd7d..01f83a507cb 100644
--- a/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
+++ b/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
@@ -64,7 +64,7 @@ public:
   Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
   Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
 
-  bool isIrrLoopHeader(const MachineBasicBlock *MBB);
+  bool isIrrLoopHeader(const MachineBasicBlock *MBB) const;
 
   void setBlockFreq(const MachineBasicBlock *MBB, uint64_t Freq);
 
diff --git a/lib/CodeGen/MachineBlockFrequencyInfo.cpp b/lib/CodeGen/MachineBlockFrequencyInfo.cpp
index 1168b01a835..c8369970601 100644
--- a/lib/CodeGen/MachineBlockFrequencyInfo.cpp
+++ b/lib/CodeGen/MachineBlockFrequencyInfo.cpp
@@ -241,8 +241,8 @@ MachineBlockFrequencyInfo::getProfileCountFromFreq(uint64_t Freq) const {
   return MBFI ? MBFI->getProfileCountFromFreq(F, Freq) : None;
 }
 
-bool
-MachineBlockFrequencyInfo::isIrrLoopHeader(const MachineBasicBlock *MBB) {
+bool MachineBlockFrequencyInfo::isIrrLoopHeader(
+    const MachineBasicBlock *MBB) const {
   assert(MBFI && "Expected analysis to be available");
   return MBFI->isIrrLoopHeader(MBB);
 }