diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -1448,6 +1448,8 @@
 
   QualType getObjCTypeParamType(const ObjCTypeParamDecl *Decl,
                                 ArrayRef<ObjCProtocolDecl *> protocols) const;
+  void adjustObjCTypeParamBoundType(const ObjCTypeParamDecl *Orig,
+                                    ObjCTypeParamDecl *New) const;
 
   bool ObjCObjectAdoptsQTypeProtocols(QualType QT, ObjCInterfaceDecl *Decl);
 
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4808,6 +4808,17 @@
   return QualType(newType, 0);
 }
 
+void ASTContext::adjustObjCTypeParamBoundType(const ObjCTypeParamDecl *Orig,
+                                              ObjCTypeParamDecl *New) const {
+  New->setTypeSourceInfo(getTrivialTypeSourceInfo(Orig->getUnderlyingType()));
+  // Update TypeForDecl after updating TypeSourceInfo.
+  auto NewTypeParamTy = cast<ObjCTypeParamType>(New->getTypeForDecl());
+  SmallVector<ObjCProtocolDecl *, 8> protocols;
+  protocols.append(NewTypeParamTy->qual_begin(), NewTypeParamTy->qual_end());
+  QualType UpdatedTy = getObjCTypeParamType(New, protocols);
+  New->setTypeForDecl(UpdatedTy.getTypePtr());
+}
+
 /// ObjCObjectAdoptsQTypeProtocols - Checks that protocols in IC's
 /// protocol list adopt all protocols in QT's qualified-id protocol
 /// list.
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3537,6 +3537,7 @@
                                 const ObjCTypeParamDecl *OTPDecl,
                                 ArrayRef<ObjCProtocolDecl *> protocols) {
   ID.AddPointer(OTPDecl);
+  ID.AddPointer(OTPDecl->getUnderlyingType().getAsOpaquePtr());
   ID.AddInteger(protocols.size());
   for (auto proto : protocols)
     ID.AddPointer(proto);
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -937,8 +937,7 @@
 
       // Override the new type parameter's bound type with the previous type,
       // so that it's consistent.
-      newTypeParam->setTypeSourceInfo(
-        S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType()));
+      S.Context.adjustObjCTypeParamBoundType(prevTypeParam, newTypeParam);
       continue;
     }
 
@@ -965,8 +964,7 @@
     }
 
     // Update the new type parameter's bound to match the previous one.
-    newTypeParam->setTypeSourceInfo(
-      S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType()));
+    S.Context.adjustObjCTypeParamBoundType(prevTypeParam, newTypeParam);
   }
 
   return false;
diff --git a/clang/test/SemaObjC/parameterized_classes_collection_literal.m b/clang/test/SemaObjC/parameterized_classes_collection_literal.m
--- a/clang/test/SemaObjC/parameterized_classes_collection_literal.m
+++ b/clang/test/SemaObjC/parameterized_classes_collection_literal.m
@@ -29,7 +29,9 @@
 @end
 
 @interface NSDictionary<K, V> : NSObject <NSCopying>
-+ (instancetype)dictionaryWithObjects:(const V [])objects forKeys:(const K [])keys count:(NSUInteger)cnt;
++ (instancetype)dictionaryWithObjects:(const V [])objects
+                              forKeys:(const K <NSCopying> [])keys
+                                count:(NSUInteger)cnt;
 @end
 
 void testArrayLiteral(void) {
@@ -50,3 +52,9 @@
     @"world" : @"blah" // expected-warning{{object of type 'NSString *' is not compatible with dictionary value type 'NSNumber *'}}
   };
 }
+
+void testCastingInDictionaryLiteral(NSString *arg) {
+  NSDictionary *dict = @{
+    (id)arg : @"foo",
+  };
+}
diff --git a/clang/test/SemaObjC/parameterized_classes_subst.m b/clang/test/SemaObjC/parameterized_classes_subst.m
--- a/clang/test/SemaObjC/parameterized_classes_subst.m
+++ b/clang/test/SemaObjC/parameterized_classes_subst.m
@@ -467,3 +467,17 @@
 - (void)mapUsingBlock2:(id)block { // expected-warning{{conflicting parameter types in implementation}}
 }
 @end
+
+// --------------------------------------------------------------------------
+// Use a type parameter as a type argument.
+// --------------------------------------------------------------------------
+// Type bounds in a category/extension are omitted. rdar://problem/54329242
+@interface ParameterizedContainer<T : id<NSCopying>>
+- (ParameterizedContainer<T> *)inInterface;
+@end
+@interface ParameterizedContainer<T> (Cat)
+- (ParameterizedContainer<T> *)inCategory;
+@end
+@interface ParameterizedContainer<U> ()
+- (ParameterizedContainer<U> *)inExtension;
+@end