diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -2894,8 +2894,8 @@
 }
 
 void CodeGenFunction::EmitForwardingCallToLambda(
-                                      const CXXMethodDecl *callOperator,
-                                      CallArgList &callArgs) {
+    const CXXMethodDecl *callOperator, CallArgList &callArgs,
+    llvm::CallBase **callOrInvoke) {
   // Get the address of the call operator.
   const CGFunctionInfo &calleeFnInfo =
     CGM.getTypes().arrangeCXXMethodDeclaration(callOperator);
@@ -2921,7 +2921,7 @@
 
   // Now emit our call.
   auto callee = CGCallee::forDirect(calleePtr, GlobalDecl(callOperator));
-  RValue RV = EmitCall(calleeFnInfo, callee, returnSlot, callArgs);
+  RValue RV = EmitCall(calleeFnInfo, callee, returnSlot, callArgs, callOrInvoke);
 
   // If necessary, copy the returned value into the slot.
   if (!resultType->isVoidType() && returnSlot.isNull()) {
@@ -2960,7 +2960,7 @@
 
   assert(!Lambda->isGenericLambda() &&
             "generic lambda interconversion to block not implemented");
-  EmitForwardingCallToLambda(CallOp, CallArgs);
+  EmitForwardingCallToLambda(CallOp, CallArgs, nullptr);
 }
 
 void CodeGenFunction::EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD) {
@@ -2990,7 +2990,16 @@
     assert(CorrespondingCallOpSpecialization);
     CallOp = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
   }
-  EmitForwardingCallToLambda(CallOp, CallArgs);
+  llvm::CallBase *CallOrInvoke = nullptr;
+  EmitForwardingCallToLambda(CallOp, CallArgs, &CallOrInvoke);
+  if (CallOrInvoke) {
+    // ThisPtr is Undef, so we need to reset incompatible attributes.
+    const auto &ToRemove =
+        llvm::AttributeFuncs::getUBImplyingAttributes().addAttribute(
+            llvm::Attribute::NonNull);
+    CallOrInvoke->getCalledFunction()->removeParamAttrs(0, ToRemove);
+    CallOrInvoke->removeParamAttrs(0, ToRemove);
+  }
 }
 
 void CodeGenFunction::EmitLambdaStaticInvokeBody(const CXXMethodDecl *MD) {
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2219,7 +2219,8 @@
   void EmitBlockWithFallThrough(llvm::BasicBlock *BB, const Stmt *S);
 
   void EmitForwardingCallToLambda(const CXXMethodDecl *LambdaCallOperator,
-                                  CallArgList &CallArgs);
+                                  CallArgList &CallArgs,
+                                  llvm::CallBase **CallOrInvoke);
   void EmitLambdaBlockInvokeBody();
   void EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD);
   void EmitLambdaStaticInvokeBody(const CXXMethodDecl *MD);
diff --git a/clang/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp b/clang/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp
--- a/clang/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp
+++ b/clang/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp
@@ -3,9 +3,9 @@
 // This code used to cause an assertion failure in EmitDelegateCallArg.
 
 // CHECK: define internal void @"?__invoke@<lambda_0>@?0??test@@YAXXZ@CA@UTrivial@@@Z"(
-// CHECK: call void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(
+// CHECK: call void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(ptr align 1 undef,
 
-// CHECK: define internal void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(
+// CHECK: define internal void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(ptr align 1 %this,
 
 struct Trivial {
   int x;