diff --git a/clang-tools-extra/clangd/unittests/CompilerTests.cpp b/clang-tools-extra/clangd/unittests/CompilerTests.cpp
--- a/clang-tools-extra/clangd/unittests/CompilerTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CompilerTests.cpp
@@ -113,6 +113,13 @@
   // No crash.
   EXPECT_EQ(buildCompilerInvocation(Inputs, Diags), nullptr);
 }
+
+TEST(BuildCompilerInvocation, SplitSwarfSingleCrash) {
+  TestTU TU;
+  TU.ExtraArgs = {"-gdwarf-4", "-gsplit-dwarf=single"};
+  TU.build(); // no-crash
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1271,7 +1271,7 @@
     F += ".dwo";
   };
   if (Arg *A = Args.getLastArg(options::OPT_gsplit_dwarf_EQ))
-    if (StringRef(A->getValue()) == "single")
+    if (StringRef(A->getValue()) == "single" && Output.isFilename())
       return Args.MakeArgString(Output.getFilename());
 
   SmallString<128> T;