diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -107,6 +107,8 @@
     Compiler.getDiagnosticOpts().ShowCarets = false;
     // Don't write out diagnostic file.
     Compiler.getDiagnosticOpts().DiagnosticSerializationFile.clear();
+    // Don't treat warnings as errors.
+    Compiler.getDiagnosticOpts().Warnings.push_back("no-error");
     // Create the compiler's actual diagnostics engine.
     Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
     if (!Compiler.hasDiagnostics())
diff --git a/clang/tools/clang-scan-deps/ClangScanDeps.cpp b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
--- a/clang/tools/clang-scan-deps/ClangScanDeps.cpp
+++ b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
@@ -506,7 +506,6 @@
         }
         AdjustedArgs.push_back("-Xclang");
         AdjustedArgs.push_back("-sys-header-deps");
-        AdjustedArgs.push_back("-Wno-error");
 
         if (!HasResourceDir) {
           StringRef ResourceDir =