diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -808,9 +808,10 @@
     return "__floating_type_";
   }
 
-  if (Ty->isPointerTy()) {
-    auto *PtrTy = cast<PointerType>(Ty);
-    Type *PointeeTy = PtrTy->getPointerElementType();
+  if (auto *PtrTy = dyn_cast<PointerType>(Ty)) {
+    if (PtrTy->isOpaque())
+      return "PointerType";
+    Type *PointeeTy = PtrTy->getNonOpaquePointerElementType();
     auto Name = solveTypeName(PointeeTy);
     if (Name == "UnknownType")
       return "PointerType";