diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 1fd7d613f9fb5..655df7e45ba7f 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -2644,7 +2644,7 @@ LangOptions getFormattingLangOpts(const FormatStyle &Style) {
 
 const char *StyleOptionHelpDescription =
     "Coding style, currently supports:\n"
-    "  LLVM, Google, Chromium, Mozilla, WebKit.\n"
+    "  LLVM, GNU, Google, Chromium, Microsoft, Mozilla, WebKit.\n"
     "Use -style=file to load style configuration from\n"
     ".clang-format file located in one of the parent\n"
     "directories of the source file (or current\n"
diff --git a/clang/tools/clang-format/clang-format-diff.py b/clang/tools/clang-format/clang-format-diff.py
index 5977ab056515e..c5331202fc1bd 100755
--- a/clang/tools/clang-format/clang-format-diff.py
+++ b/clang/tools/clang-format/clang-format-diff.py
@@ -56,8 +56,8 @@ def main():
   parser.add_argument('-v', '--verbose', action='store_true',
                       help='be more verbose, ineffective without -i')
   parser.add_argument('-style',
-                      help='formatting style to apply (LLVM, Google, Chromium, '
-                      'Mozilla, WebKit)')
+                      help='formatting style to apply (LLVM, GNU, Google, Chromium, '
+                      'Microsoft, Mozilla, WebKit)')
   parser.add_argument('-binary', default='clang-format',
                       help='location of binary to use for clang-format')
   args = parser.parse_args()