diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
index d502be65a78..65a70fbfa6d 100644
--- a/include/llvm/ADT/DenseMap.h
+++ b/include/llvm/ADT/DenseMap.h
@@ -617,8 +617,9 @@ public:
     this->destroyAll();
 
     // Reduce the number of buckets.
-    unsigned NewNumBuckets
-      = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1));
+    unsigned NewNumBuckets = 0;
+    if (OldNumEntries)
+      NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1));
     if (NewNumBuckets == NumBuckets) {
       this->BaseT::initEmpty();
       return;