diff --git a/include/llvm/ADT/SmallVector.h b/include/llvm/ADT/SmallVector.h
index 89acefd0618..c4507a917f3 100644
--- a/include/llvm/ADT/SmallVector.h
+++ b/include/llvm/ADT/SmallVector.h
@@ -57,17 +57,18 @@ protected:
   // something else.  An array of char would work great, but might not be
   // aligned sufficiently.  Instead, we either use GCC extensions, or some
   // number of union instances for the space, which guarantee maximal alignment.
+  struct U {
 #ifdef __GNUC__
-  typedef char U;
-  U FirstEl __attribute__((aligned));
+    char X __attribute__((aligned));
 #else
-  union U {
-    double D;
-    long double LD;
-    long long L;
-    void *P;
-  } FirstEl;
+    union U {
+      double D;
+      long double LD;
+      long long L;
+      void *P;
+    } X;
 #endif
+  } FirstEl;
   // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
   
 protected: