diff --git a/llvm/include/Support/hash_map b/llvm/include/Support/hash_map
index aefcc289e2ed..d6a0ac0faf49 100644
--- a/llvm/include/Support/hash_map
+++ b/llvm/include/Support/hash_map
@@ -1,6 +1,20 @@
+//===-- Support/hash_map - "Portable" wrapper around hash_map ---*- C++ -*-===//
+//
+// This file provides a wrapper around the mysterious <hash_map> header file
+// that seems to move around between GCC releases into and out of namespaces at
+// will.  #including this header will cause hash_map to be available in the
+// global namespace.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_HASHMAP_H
+#define SUPPORT_HASHMAP_H
+
 #if __GNUC__ == 3
 #include <ext/hash_map>
 using __gnu_cxx::hash_map;
 #else
 #include <hash_map>
 #endif
+
+#endif
diff --git a/llvm/include/Support/hash_set b/llvm/include/Support/hash_set
index f95cc363c741..094f89219950 100644
--- a/llvm/include/Support/hash_set
+++ b/llvm/include/Support/hash_set
@@ -1,3 +1,14 @@
+//===-- Support/hash_set - "Portable" wrapper around hash_set ---*- C++ -*-===//
+//
+// This file provides a wrapper around the mysterious <hash_set> header file
+// that seems to move around between GCC releases into and out of namespaces at
+// will.  #including this header will cause hash_set to be available in the
+// global namespace.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_HASHSET_H
+#define SUPPORT_HASHSET_H
 #if __GNUC__==3
 #include <ext/hash_set>
 using __gnu_cxx::hash_set;