diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp
index 15aed3436c7..83706deb3f7 100644
--- a/lib/CodeGen/TailDuplication.cpp
+++ b/lib/CodeGen/TailDuplication.cpp
@@ -459,7 +459,8 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
   // duplicate only one, because one branch instruction can be eliminated to
   // compensate for the duplication.
   unsigned MaxDuplicateCount;
-  if (MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
+  if (TailDuplicateSize.getNumOccurrences() == 0 &&
+      MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
     MaxDuplicateCount = 1;
   else
     MaxDuplicateCount = TailDuplicateSize;