diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -1297,7 +1297,7 @@
   bool loopIsFiniteByAssumption(const Loop *L);
 
   class FoldID {
-    SmallVector<unsigned, 4> Bits;
+    SmallVector<unsigned, 5> Bits;
 
   public:
     void addInteger(unsigned long I) {