diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -486,6 +486,35 @@
   }
 };
 
+// For use in NPM transition.
+// TODO: use a codegen version of PassRegistry.def/PassBuilder::is*Pass() once
+// it exists.
+static bool IsCodegenPass(StringRef Pass) {
+  return Pass.startswith("x86-") || Pass.startswith("xcore-") ||
+         Pass.startswith("wasm-") || Pass.startswith("systemz-") ||
+         Pass.startswith("ppc-") || Pass.startswith("nvvm-") ||
+         Pass.startswith("nvptx-") || Pass.startswith("mips-") ||
+         Pass.startswith("lanai-") || Pass.startswith("hexagon-") ||
+         Pass.startswith("bpf-") || Pass.startswith("avr-") ||
+         Pass.startswith("thumb2-") || Pass.startswith("arm-") ||
+         Pass.startswith("si-") || Pass.startswith("gcn-") ||
+         Pass.startswith("amdgpu-") || Pass.startswith("aarch64-") ||
+         Pass.contains("ehprepare") || Pass == "safe-stack" ||
+         Pass == "cost-model" || Pass == "codegenprepare" ||
+         Pass == "interleaved-load-combine" || Pass == "unreachableblockelim" ||
+         Pass == "scalarize-masked-mem-intrin";
+}
+
+// For use in NPM transition.
+static bool CodegenPassSpecifiedInPassList() {
+  for (const auto &P : PassList) {
+    StringRef Arg = P->getPassArgument();
+    if (IsCodegenPass(Arg))
+      return true;
+  }
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 // main for opt
 //
@@ -685,7 +714,8 @@
   if (OutputThinLTOBC)
     M->addModuleFlag(Module::Error, "EnableSplitLTOUnit", SplitLTOUnit);
 
-  if (EnableNewPassManager || PassPipeline.getNumOccurrences() > 0) {
+  if ((EnableNewPassManager && !CodegenPassSpecifiedInPassList()) ||
+      PassPipeline.getNumOccurrences() > 0) {
     if (PassPipeline.getNumOccurrences() > 0 && PassList.size() > 0) {
       errs()
           << "Cannot specify passes via both -foo-pass and --passes=foo-pass";