Index: cfe/trunk/test/Tooling/clang-diff-topdown.cpp
===================================================================
--- cfe/trunk/test/Tooling/clang-diff-topdown.cpp
+++ cfe/trunk/test/Tooling/clang-diff-topdown.cpp
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -E %s > %t.src.cpp
 // RUN: %clang_cc1 -E %s > %t.dst.cpp -DDEST
-// RUN: clang-diff -dump-matches -stop-after=topdown %t.src.cpp %t.dst.cpp -- -std=c++11 | FileCheck %s
+// RUN: clang-diff -dump-matches -stop-diff-after=topdown %t.src.cpp %t.dst.cpp -- -std=c++11 | FileCheck %s
 //
 // Test the top-down matching of identical subtrees only.
 
Index: cfe/trunk/tools/clang-diff/ClangDiff.cpp
===================================================================
--- cfe/trunk/tools/clang-diff/ClangDiff.cpp
+++ cfe/trunk/tools/clang-diff/ClangDiff.cpp
@@ -50,7 +50,7 @@
                                             cl::Optional,
                                             cl::cat(ClangDiffCategory));
 
-static cl::opt<std::string> StopAfter("stop-after",
+static cl::opt<std::string> StopAfter("stop-diff-after",
                                       cl::desc("<topdown|bottomup>"),
                                       cl::Optional, cl::init(""),
                                       cl::cat(ClangDiffCategory));