diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -93,8 +93,9 @@
   const driver::JobList &Jobs = Compilation->getJobs();
   const driver::ActionList &Actions = Compilation->getActions();
   bool OffloadCompilation = false;
+  bool ExternalAssembler = false;
   if (Jobs.size() > 1) {
-    for (auto A : Actions){
+    for (const auto *A : Actions) {
       // On MacOSX real actions may end up being wrapped in BindArchAction
       if (isa<driver::BindArchAction>(A))
         A = *A->input_begin();
@@ -115,10 +116,15 @@
         OffloadCompilation = true;
         break;
       }
+      if (isa<driver::AssembleJobAction>(A)) {
+        ExternalAssembler = true;
+        break;
+      }
     }
   }
+  bool MultipleJobsAllowed = OffloadCompilation || ExternalAssembler;
   if (Jobs.size() == 0 || !isa<driver::Command>(*Jobs.begin()) ||
-      (Jobs.size() > 1 && !OffloadCompilation)) {
+      (Jobs.size() > 1 && !MultipleJobsAllowed)) {
     SmallString<256> error_msg;
     llvm::raw_svector_ostream error_stream(error_msg);
     Jobs.Print(error_stream, "; ", true);
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
@@ -258,6 +258,31 @@
   EXPECT_TRUE(Consumer.SawSourceManager);
 }
 
+TEST(ToolInvocation, AllowExternalAssembler) {
+  auto OverlayFS = llvm::makeIntrusiveRefCnt<llvm::vfs::OverlayFileSystem>(
+      llvm::vfs::getRealFileSystem());
+  auto InMemoryFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
+  OverlayFS->pushOverlay(InMemoryFS);
+  auto Files =
+      llvm::makeIntrusiveRefCnt<FileManager>(FileSystemOptions(), OverlayFS);
+
+  std::vector<std::string> Args;
+  Args.push_back("tool-executable");
+  Args.push_back("-fno-integrated-as");
+  Args.push_back("-c");
+  Args.push_back("test.cpp");
+
+  // We're not matching the "-c" argument with `clang::EmitObjAction` in order
+  // to avoid linking the clangCodeGen library. This does not affect the
+  // command-line handling code under test.
+  clang::tooling::ToolInvocation Invocation(
+      Args, std::make_unique<SyntaxOnlyAction>(), Files.get());
+  InMemoryFS->addFile("test.cpp", 0,
+                      llvm::MemoryBuffer::getMemBuffer("int main() {}\n"));
+
+  EXPECT_TRUE(Invocation.run());
+}
+
 struct VerifyEndCallback : public SourceFileCallbacks {
   VerifyEndCallback() : BeginCalled(0), EndCalled(0), Matched(false) {}
   bool handleBeginSource(CompilerInstance &CI) override {