Index: clangd/ClangdUnit.cpp
===================================================================
--- clangd/ClangdUnit.cpp
+++ clangd/ClangdUnit.cpp
@@ -425,8 +425,21 @@
 std::unique_ptr<CompilerInvocation>
 buildCompilerInvocation(const ParseInputs &Inputs) {
   std::vector<const char *> ArgStrs;
-  for (const auto &S : Inputs.CompileCommand.CommandLine)
-    ArgStrs.push_back(S.c_str());
+  const auto &CommandLine = Inputs.CompileCommand.CommandLine;
+  for (size_t I = 0, E = CommandLine.size(); I != E; I++) {
+    // According to https://clang.llvm.org/docs/ClangPlugins.html
+    // -Xclang {-load, -plugin, -plugin-arg-<plugin-name>, -add-plugin} -Xclang
+    // <arbitrary-argument>
+    if (I + 4 < E && CommandLine[I] == "-Xclang" &&
+        (CommandLine[I + 1] == "-load" || CommandLine[I + 1] == "-plugin" ||
+         llvm::StringRef(CommandLine[I + 1]).startswith("-plugin-arg-") ||
+         CommandLine[I + 1] == "-add-plugin") &&
+        CommandLine[I + 2] == "-Xclang") {
+      I += 3;
+      continue;
+    }
+    ArgStrs.push_back(CommandLine[I].c_str());
+  }
 
   if (Inputs.FS->setCurrentWorkingDirectory(Inputs.CompileCommand.Directory)) {
     log("Couldn't set working directory when creating compiler invocation.");
Index: unittests/clangd/ClangdTests.cpp
===================================================================
--- unittests/clangd/ClangdTests.cpp
+++ unittests/clangd/ClangdTests.cpp
@@ -1037,6 +1037,27 @@
 }
 #endif
 
+TEST_F(ClangdVFSTest, FlagsWithPlugins) {
+  MockFSProvider FS;
+  ErrorCheckingDiagConsumer DiagConsumer;
+  MockCompilationDatabase CDB;
+  CDB.ExtraClangFlags = {
+      "-Xclang",
+      "-add-plugin",
+      "-Xclang",
+      "random-plugin",
+  };
+  ClangdServer Server(CDB, FS, DiagConsumer, ClangdServer::optsForTest());
+
+  auto FooCpp = testPath("foo.cpp");
+  const auto SourceContents = "int main() { return 0; }";
+  FS.Files[FooCpp] = FooCpp;
+  Server.addDocument(FooCpp, SourceContents);
+  auto Result = dumpASTWithoutMemoryLocs(Server, FooCpp);
+  EXPECT_TRUE(Server.blockUntilIdleForTest()) << "Waiting for diagnostics";
+  EXPECT_NE(Result, "<no-ast>");
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang