diff --git a/llvm/include/llvm/ADT/SmallString.h b/llvm/include/llvm/ADT/SmallString.h
--- a/llvm/include/llvm/ADT/SmallString.h
+++ b/llvm/include/llvm/ADT/SmallString.h
@@ -275,7 +275,9 @@
   /// Implicit conversion to StringRef.
   operator StringRef() const { return str(); }
 
-  explicit operator std::string() const { return str().str(); }
+  explicit operator std::string() const {
+    return std::string(this->begin(), this->size());
+  }
 
   // Extra operators.
   const SmallString &operator=(StringRef RHS) {