Index: docs/CommandGuide/llvm-dwarfdump.rst
===================================================================
--- docs/CommandGuide/llvm-dwarfdump.rst
+++ docs/CommandGuide/llvm-dwarfdump.rst
@@ -69,7 +69,7 @@
             Lookup <address> in the debug information and print out the file,
             function, block, and line table details.
 
-.. option:: -o <path>, --out-file=<path>
+.. option:: -o <path>
 
             Redirect output to a file specified by <path>.
 
Index: test/tools/llvm-dwarfdump/cmdline.test
===================================================================
--- test/tools/llvm-dwarfdump/cmdline.test
+++ test/tools/llvm-dwarfdump/cmdline.test
@@ -1,5 +1,5 @@
-RUN: llvm-dwarfdump -h 2>&1 | FileCheck --check-prefix=HELP %s
-RUN: llvm-dwarfdump --help 2>&1 | FileCheck --check-prefix=HELP %s
+RUN: llvm-dwarfdump -h 2>&1 | FileCheck --check-prefix=HELP %s --implicit-check-not=out-file
+RUN: llvm-dwarfdump --help 2>&1 | FileCheck --check-prefix=HELP %s --implicit-check-not=out-file
 HELP: USAGE: llvm-dwarfdump{{[^ ]*}} [options] <input object files or .dSYM bundles>
 HELP-NOT: -reverse-iterate
 HELP: Color Options
@@ -13,6 +13,7 @@
 HELP: -ignore-case
 HELP: -lookup
 HELP: -name
+HELP: -o=<filename>
 HELP: -parent-recurse-depth=<N>
 HELP: -recurse-depth=<N>
 HELP: -regex
Index: tools/llvm-dwarfdump/llvm-dwarfdump.cpp
===================================================================
--- tools/llvm-dwarfdump/llvm-dwarfdump.cpp
+++ tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -160,12 +160,11 @@
                 "available file, function, block and line table details."),
            value_desc("address"), cat(DwarfDumpCategory));
 static opt<std::string>
-    OutputFilename("out-file", cl::init("-"),
+    OutputFilename("o", cl::init("-"),
                    cl::desc("Redirect output to the specified file."),
-                   cl::value_desc("filename"));
-static alias OutputFilenameAlias("o", desc("Alias for -out-file."),
-                                 aliasopt(OutputFilename),
-                                 cat(DwarfDumpCategory));
+                   cl::value_desc("filename"), cat(DwarfDumpCategory));
+static alias OutputFilenameAlias("out-file", desc("Alias for -o."),
+                                 aliasopt(OutputFilename));
 static opt<bool>
     UseRegex("regex",
              desc("Treat any <pattern> strings as regular expressions when "