diff --git a/lib/IRGen/Fulfillment.cpp b/lib/IRGen/Fulfillment.cpp
index b52de85..739b4f5 100644
--- a/lib/IRGen/Fulfillment.cpp
+++ b/lib/IRGen/Fulfillment.cpp
@@ -70,12 +70,12 @@
   case TypeKind::Tuple:
     return cast<TupleType>(type)->getNumElements() == 0;
 
-  // Nominal types might have parents.
+  // Nominal types might have generic parents.
   case TypeKind::Class:
   case TypeKind::Enum:
   case TypeKind::Protocol:
   case TypeKind::Struct:
-    return !cast<NominalType>(type)->getParent();
+    return !cast<NominalType>(type)->getDecl()->isGenericContext();
 
   // Bound generic types have type arguments.
   case TypeKind::BoundGenericClass:
@@ -125,6 +125,13 @@
     return hadFulfillment;
   }
 
+  if (keys.isInterestingType(type)) {
+    if (auto superclassTy = keys.getSuperclassBound(type)) {
+      return searchNominalTypeMetadata(IGM, superclassTy, source,
+                                       std::move(path), keys);
+    }
+  }
+
   // Inexact metadata will be a problem if we ever try to use this
   // to remember that we already have the metadata for something.
   if (isa<NominalType>(type) || isa<BoundGenericType>(type)) {
@@ -289,21 +296,6 @@
   }
 }
 
-bool FulfillmentMap::Everything::isInterestingType(CanType type) const {
-  return true;
-}
-bool FulfillmentMap::Everything::hasInterestingType(CanType type) const {
-  return true;
-}
-bool FulfillmentMap::Everything
-                   ::hasLimitedInterestingConformances(CanType type) const {
-  return false;
-}
-GenericSignature::ConformsToArray
-FulfillmentMap::Everything::getInterestingConformances(CanType type) const{
-  return {};
-}
-
 void FulfillmentMap::dump() const {
   auto &out = llvm::errs();
   for (auto &entry : Fulfillments) {
diff --git a/lib/IRGen/Fulfillment.h b/lib/IRGen/Fulfillment.h
index 858e1d5..65737b6 100644
--- a/lib/IRGen/Fulfillment.h
+++ b/lib/IRGen/Fulfillment.h
@@ -66,17 +66,10 @@
     virtual GenericSignature::ConformsToArray
       getInterestingConformances(CanType type) const = 0;
 
-    virtual ~InterestingKeysCallback() = default;
-  };
+    /// Return the limited interesting conformances for an interesting type.
+    virtual CanType getSuperclassBound(CanType type) const = 0;
 
-  /// An implementation of InterestingKeysCallback that returns everything
-  /// fulfillable.
-  struct Everything : InterestingKeysCallback {
-    bool isInterestingType(CanType type) const override;
-    bool hasInterestingType(CanType type) const override;
-    bool hasLimitedInterestingConformances(CanType type) const override;
-    GenericSignature::ConformsToArray
-      getInterestingConformances(CanType type) const override;
+    virtual ~InterestingKeysCallback() = default;
   };
 
   FulfillmentMap() = default;
diff --git a/lib/IRGen/GenProto.cpp b/lib/IRGen/GenProto.cpp
index 05cc66a..3982e34 100644
--- a/lib/IRGen/GenProto.cpp
+++ b/lib/IRGen/GenProto.cpp
@@ -95,6 +95,12 @@
     return Generics->getConformsTo(t, M);
   }
 
+  CanType getSuperclassBound(Type t) {
+    if (auto superclassTy = Generics->getSuperclassBound(t, M))
+      return superclassTy->getCanonicalType();
+    return CanType();
+  }
+
 public:
   PolymorphicConvention(IRGenModule &IGM, CanSILFunctionType fnType);
 
@@ -291,6 +297,9 @@
     getInterestingConformances(CanType type) const override {
       return Self.getConformsTo(type);
     }
+    CanType getSuperclassBound(CanType type) const override {
+      return Self.getSuperclassBound(type);
+    }
   } callbacks(*this);
   return Fulfillments.searchTypeMetadata(IGM, type, isExact, sourceIndex,
                                          std::move(path), callbacks);
@@ -367,6 +376,15 @@
         return;
       }
 
+      if (isa<GenericTypeParamType>(type)) {
+        if (auto superclassTy = getSuperclassBound(type)) {
+          considerNewTypeSource(MetadataSource::Kind::ClassPointer,
+                                paramIndex, superclassTy, IsInexact);
+          return;
+
+        }
+      }
+
       // Thick metatypes are sources of metadata.
       if (auto metatypeTy = dyn_cast<MetatypeType>(type)) {
         if (metatypeTy->getRepresentation() != MetatypeRepresentation::Thick)
@@ -1284,6 +1302,11 @@
           getInterestingConformances(CanType type) const override {
             llvm_unreachable("no limits");
           }
+          CanType getSuperclassBound(CanType type) const override {
+            if (auto superclassTy = cast<ArchetypeType>(type)->getSuperclass())
+              return superclassTy->getCanonicalType();
+            return CanType();
+          }
         } callback;
         Fulfillments->searchTypeMetadata(IGM, ConcreteType, IsExact,
                                          /*sourceIndex*/ 0, MetadataPath(),
@@ -2023,7 +2046,10 @@
   case Component::Kind::NominalTypeArgument:
   case Component::Kind::NominalTypeArgumentConformance: {
     assert(sourceKey.Kind == LocalTypeDataKind::forTypeMetadata());
-    auto *nominal = sourceKey.Type.getAnyNominal();
+    auto type = sourceKey.Type;
+    if (auto archetypeTy = dyn_cast<ArchetypeType>(type))
+      type = archetypeTy->getSuperclass()->getCanonicalType();
+    auto *nominal = type.getAnyNominal();
     auto reqtIndex = component.getPrimaryIndex();
 
     GenericTypeRequirements requirements(IGF.IGM, nominal);
diff --git a/lib/IRGen/LocalTypeData.cpp b/lib/IRGen/LocalTypeData.cpp
index 3deddfb..fe2fc05 100644
--- a/lib/IRGen/LocalTypeData.cpp
+++ b/lib/IRGen/LocalTypeData.cpp
@@ -254,12 +254,34 @@
                                                     CanType type,
                                                     IsExact_t isExact,
                                                     llvm::Value *metadata) {
+  struct Callback : FulfillmentMap::InterestingKeysCallback {
+    bool isInterestingType(CanType type) const override {
+      return true;
+    }
+    bool hasInterestingType(CanType type) const override {
+      return true;
+    }
+    bool hasLimitedInterestingConformances(CanType type) const override {
+      return false;
+    }
+    GenericSignature::ConformsToArray
+    getInterestingConformances(CanType type) const override {
+      llvm_unreachable("no limits");
+    }
+    CanType getSuperclassBound(CanType type) const override {
+      if (auto arch = dyn_cast<ArchetypeType>(type))
+        if (auto superclassTy = arch->getSuperclass())
+          return superclassTy->getCanonicalType();
+      return CanType();
+    }
+  } callbacks;
+
   // Look for anything at all that's fulfilled by this.  If we don't find
   // anything, stop.
   FulfillmentMap fulfillments;
   if (!fulfillments.searchTypeMetadata(IGF.IGM, type, isExact,
                                        /*source*/ 0, MetadataPath(),
-                                       FulfillmentMap::Everything())) {
+                                       callbacks)) {
     return;
   }
 
diff --git a/lib/SIL/SILFunctionType.cpp b/lib/SIL/SILFunctionType.cpp
index 4a51087..dbb400d 100644
--- a/lib/SIL/SILFunctionType.cpp
+++ b/lib/SIL/SILFunctionType.cpp
@@ -100,6 +100,9 @@
   assert(getRepresentation() == SILFunctionTypeRepresentation::WitnessMethod);
   auto selfTy = getSelfInstanceType();
   if (auto paramTy = dyn_cast<GenericTypeParamType>(selfTy)) {
+    auto superclass = GenericSig->getSuperclassBound(paramTy, M);
+    if (superclass)
+      return nullptr;
     assert(paramTy->getDepth() == 0 && paramTy->getIndex() == 0);
     auto protos = GenericSig->getConformsTo(paramTy, M);
     assert(protos.size() == 1);
diff --git a/test/IRGen/class_bounded_generics.swift b/test/IRGen/class_bounded_generics.swift
index 184f8ae..573a13b 100644
--- a/test/IRGen/class_bounded_generics.swift
+++ b/test/IRGen/class_bounded_generics.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -assume-parsing-unqualified-ownership-sil -emit-ir -primary-file %s -disable-objc-attr-requires-foundation-module | %FileCheck %s
+// RUN: %target-swift-frontend -emit-ir -primary-file %s -disable-objc-attr-requires-foundation-module | %FileCheck %s
 
 // REQUIRES: CPU=x86_64
 // XFAIL: linux
@@ -9,7 +9,7 @@
 protocol ClassBound2 : class {
   func classBoundMethod2()
 }
-protocol ClassBoundBinary : class, ClassBound {
+protocol ClassBoundBinary : ClassBound {
   func classBoundBinaryMethod(_ x: Self)
 }
 @objc protocol ObjCClassBound {
@@ -214,7 +214,7 @@
 }
 
 // CHECK-LABEL: define hidden swiftcc { i64, %objc_object*, i64 } @_T022class_bounded_generics0A28_generic_field_struct_fields{{[_0-9a-zA-Z]*}}F(i64, %objc_object*, i64, %swift.type* %T, i8** %T.ClassBound)
-func class_generic_field_struct_fields<T : ClassBound>
+func class_generic_field_struct_fields<T>
 (_ x:ClassGenericFieldStruct<T>) -> (Int, T, Int) {
   return (x.x, x.y, x.z)
 }
@@ -226,7 +226,7 @@
 }
 
 // CHECK-LABEL: define hidden swiftcc { i64, %objc_object*, i64 } @_T022class_bounded_generics0a15_generic_field_A7_fields{{[_0-9a-zA-Z]*}}F(%T22class_bounded_generics017ClassGenericFieldD0C*)
-func class_generic_field_class_fields<T : ClassBound>
+func class_generic_field_class_fields<T>
 (_ x:ClassGenericFieldClass<T>) -> (Int, T, Int) {
   return (x.x, x.y, x.z)
   // CHECK: getelementptr inbounds %T22class_bounded_generics017ClassGenericFieldD0C, %T22class_bounded_generics017ClassGenericFieldD0C* %0, i32 0, i32 1
@@ -273,3 +273,36 @@
     s = S.init()
   }
 }
+
+// CHECK-LABEL: define hidden swiftcc void @_T022class_bounded_generics14takes_metatypeyxmlF(%swift.type*, %swift.type* %T)
+func takes_metatype<T>(_: T.Type) {}
+
+// CHECK-LABEL: define hidden swiftcc void @_T022class_bounded_generics023archetype_with_generic_A11_constraintyx1t_tAA1ACyq_GRbzr0_lF(%T22class_bounded_generics1AC.2*, %swift.type* %T)
+// CHECK:      [[ISA_ADDR:%.*]] = bitcast %T22class_bounded_generics1AC.2* %0 to %swift.type**
+// CHECK-NEXT: [[ISA:%.*]] = load %swift.type*, %swift.type** [[ISA_ADDR]]
+// CHECK-NEXT: call swiftcc void @_T022class_bounded_generics14takes_metatypeyxmlF(%swift.type* %T, %swift.type* %T)
+// CHECK-NEXT: [[ISA_PTR:%.*]] = bitcast %swift.type* [[ISA]] to %swift.type**
+// CHECK-NEXT: [[U_ADDR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[ISA_PTR]], i64 10
+// CHECK-NEXT: [[U:%.*]] = load %swift.type*, %swift.type** [[U_ADDR]]
+// CHECK-NEXT: call swiftcc void @_T022class_bounded_generics14takes_metatypeyxmlF(%swift.type* %U, %swift.type* %U)
+// CHECK:      ret void
+
+func archetype_with_generic_class_constraint<T, U>(t: T) where T : A<U> {
+  takes_metatype(T.self)
+  takes_metatype(U.self)
+}
+
+// CHECK-LABEL: define hidden swiftcc void @_T022class_bounded_generics029calls_archetype_with_generic_A11_constraintyAA1ACyxG1a_tlF(%T22class_bounded_generics1AC*) #0 {
+// CHECK:      [[ISA_ADDR:%.*]] = getelementptr inbounds %T22class_bounded_generics1AC, %T22class_bounded_generics1AC* %0, i32 0, i32 0, i32 0
+// CHECK-NEXT: [[ISA:%.*]] = load %swift.type*, %swift.type** [[ISA_ADDR]]
+// CHECK:      [[SELF:%.*]] = bitcast %T22class_bounded_generics1AC* %0 to %T22class_bounded_generics1AC.2*
+// CHECK-NEXT: [[ISA_PTR:%.*]] = bitcast %swift.type* [[ISA]] to %swift.type**
+// CHECK-NEXT: [[T_ADDR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[ISA_PTR]], i64 10
+// CHECK-NEXT: [[T:%.*]] = load %swift.type*, %swift.type** [[T_ADDR]]
+// CHECK-NEXT: [[A_OF_T:%.*]] = call %swift.type* @_T022class_bounded_generics1ACMa(%swift.type* [[T]])
+// CHECK-NEXT: call swiftcc void @_T022class_bounded_generics023archetype_with_generic_A11_constraintyx1t_tAA1ACyq_GRbzr0_lF(%T22class_bounded_generics1AC.2* [[SELF]], %swift.type* [[A_OF_T]])
+// CHECK:      ret void
+
+func calls_archetype_with_generic_class_constraint<T>(a: A<T>) {
+  archetype_with_generic_class_constraint(t: a)
+}