diff --git a/clang-tools-extra/clangd/unittests/CompileCommandsTests.cpp b/clang-tools-extra/clangd/unittests/CompileCommandsTests.cpp
--- a/clang-tools-extra/clangd/unittests/CompileCommandsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CompileCommandsTests.cpp
@@ -79,6 +79,13 @@
     EXPECT_THAT(Cmd, Not(Contains(Stripped)));
 }
 
+TEST(CommandMangler, StripShowIncludes) {
+  auto Mangler = CommandMangler::forTests();
+  std::vector<std::string> Cmd = {"clang-cl", "/showIncludes", "foo.cc"};
+  Mangler.adjust(Cmd);
+  EXPECT_THAT(Cmd, Not(Contains("/showIncludes")));
+}
+
 TEST(CommandMangler, ClangPath) {
   auto Mangler = CommandMangler::forTests();
   Mangler.ClangPath = testPath("fake/clang");
diff --git a/clang/lib/Tooling/ArgumentsAdjusters.cpp b/clang/lib/Tooling/ArgumentsAdjusters.cpp
--- a/clang/lib/Tooling/ArgumentsAdjusters.cpp
+++ b/clang/lib/Tooling/ArgumentsAdjusters.cpp
@@ -98,7 +98,7 @@
       StringRef Arg = Args[i];
       // All dependency-file options begin with -M. These include -MM,
       // -MF, -MG, -MP, -MT, -MQ, -MD, and -MMD.
-      if (!Arg.startswith("-M")) {
+      if (!Arg.startswith("-M") && Arg != "/showIncludes") {
         AdjustedArgs.push_back(Args[i]);
         continue;
       }
diff --git a/clang/unittests/Tooling/ToolingTest.cpp b/clang/unittests/Tooling/ToolingTest.cpp
--- a/clang/unittests/Tooling/ToolingTest.cpp
+++ b/clang/unittests/Tooling/ToolingTest.cpp
@@ -530,6 +530,34 @@
   EXPECT_TRUE(HasFlag("-w"));
 }
 
+// Check getClangStripDependencyFileAdjuster strips /showIncludes
+TEST(ClangToolTest, StripDependencyFileAdjusterShowIncludes) {
+  FixedCompilationDatabase Compilations("/", {"/showIncludes", "-c"});
+
+  ClangTool Tool(Compilations, std::vector<std::string>(1, "/a.cc"));
+  Tool.mapVirtualFile("/a.cc", "void a() {}");
+
+  std::unique_ptr<FrontendActionFactory> Action(
+      newFrontendActionFactory<SyntaxOnlyAction>());
+
+  CommandLineArguments FinalArgs;
+  ArgumentsAdjuster CheckFlagsAdjuster =
+    [&FinalArgs](const CommandLineArguments &Args, StringRef /*unused*/) {
+      FinalArgs = Args;
+      return Args;
+    };
+  Tool.clearArgumentsAdjusters();
+  Tool.appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
+  Tool.appendArgumentsAdjuster(CheckFlagsAdjuster);
+  Tool.run(Action.get());
+
+  auto HasFlag = [&FinalArgs](const std::string &Flag) {
+    return llvm::find(FinalArgs, Flag) != FinalArgs.end();
+  };
+  EXPECT_FALSE(HasFlag("/showIncludes"));
+  EXPECT_TRUE(HasFlag("-c"));
+}
+
 // Check getClangStripPluginsAdjuster strips plugin related args.
 TEST(ClangToolTest, StripPluginsAdjuster) {
   FixedCompilationDatabase Compilations(