Index: mlir/docs/PDLL.md
===================================================================
--- mlir/docs/PDLL.md
+++ mlir/docs/PDLL.md
@@ -1225,7 +1225,7 @@
     - Imported `Type` constraints utilize the `cppClassName` field for native type translation.
 
   * `AttrInterface`/`OpInterface`/`TypeInterface` constraints
-    - Imported interfaces utilize the `cppClassName` field for native type translation.
+    - Imported interfaces utilize the `cppInterfaceName` field for native type translation.
 
 #### Defining Constraints Inline
 
Index: mlir/include/mlir/IR/OpBase.td
===================================================================
--- mlir/include/mlir/IR/OpBase.td
+++ mlir/include/mlir/IR/OpBase.td
@@ -1949,7 +1949,7 @@
   string description = "";
 
   // The name given to the c++ interface class.
-  string cppClassName = name;
+  string cppInterfaceName = name;
 
   // The C++ namespace that this interface should be placed into.
   //
@@ -1970,13 +1970,25 @@
 }
 
 // AttrInterface represents an interface registered to an attribute.
-class AttrInterface<string name> : Interface<name>, InterfaceTrait<name>;
+class AttrInterface<string name> : Interface<name>, InterfaceTrait<name>,
+	Attr<CPred<"$_self.isa<"
+		# !if(!empty(cppNamespace),"", cppNamespace # "::") # name # ">()">,
+			name # " instance">
+{
+	let storageType = !if(!empty(cppNamespace), "", cppNamespace # "::") # name;
+	let returnType = storageType;
+	let convertFromStorage = "$_self";
+}
 
 // OpInterface represents an interface registered to an operation.
 class OpInterface<string name> : Interface<name>, OpInterfaceTrait<name>;
 
 // TypeInterface represents an interface registered to a type.
-class TypeInterface<string name> : Interface<name>, InterfaceTrait<name>;
+class TypeInterface<string name> : Interface<name>, InterfaceTrait<name>,
+	Type<CPred<"$_self.isa<"
+		# !if(!empty(cppNamespace),"", cppNamespace # "::") # name # ">()">,
+			name # " instance",
+				!if(!empty(cppNamespace),"", cppNamespace # "::") # name>;
 
 // Whether to declare the interface methods in the user entity's header. This
 // class simply wraps an Interface but is used to indicate that the method
@@ -1992,27 +2004,27 @@
 class DeclareAttrInterfaceMethods<AttrInterface interface,
                                   list<string> overridenMethods = []>
       : DeclareInterfaceMethods<overridenMethods>,
-        AttrInterface<interface.cppClassName> {
+        AttrInterface<interface.cppInterfaceName> {
     let description = interface.description;
-    let cppClassName = interface.cppClassName;
+    let cppInterfaceName = interface.cppInterfaceName;
     let cppNamespace = interface.cppNamespace;
     let methods = interface.methods;
 }
 class DeclareOpInterfaceMethods<OpInterface interface,
                                 list<string> overridenMethods = []>
       : DeclareInterfaceMethods<overridenMethods>,
-        OpInterface<interface.cppClassName> {
+        OpInterface<interface.cppInterfaceName> {
     let description = interface.description;
-    let cppClassName = interface.cppClassName;
+    let cppInterfaceName = interface.cppInterfaceName;
     let cppNamespace = interface.cppNamespace;
     let methods = interface.methods;
 }
 class DeclareTypeInterfaceMethods<TypeInterface interface,
                                   list<string> overridenMethods = []>
       : DeclareInterfaceMethods<overridenMethods>,
-        TypeInterface<interface.cppClassName> {
+        TypeInterface<interface.cppInterfaceName> {
     let description = interface.description;
-    let cppClassName = interface.cppClassName;
+    let cppInterfaceName = interface.cppInterfaceName;
     let cppNamespace = interface.cppNamespace;
     let methods = interface.methods;
 }
Index: mlir/lib/TableGen/Interfaces.cpp
===================================================================
--- mlir/lib/TableGen/Interfaces.cpp
+++ mlir/lib/TableGen/Interfaces.cpp
@@ -81,7 +81,7 @@
 
 // Return the name of this interface.
 StringRef Interface::getName() const {
-  return def->getValueAsString("cppClassName");
+  return def->getValueAsString("cppInterfaceName");
 }
 
 // Return the C++ namespace of this interface.
Index: mlir/lib/Tools/PDLL/Parser/Parser.cpp
===================================================================
--- mlir/lib/Tools/PDLL/Parser/Parser.cpp
+++ mlir/lib/Tools/PDLL/Parser/Parser.cpp
@@ -873,38 +873,43 @@
                           addTypeConstraint(result));
     }
   }
+
+  auto shouldBeSkipped = [this](llvm::Record *def) {
+    return def->isAnonymous() || curDeclScope->lookup(def->getName()) ||
+           def->isSubClassOf("DeclareInterfaceMethods");
+  };
+
   /// Attr constraints.
   for (llvm::Record *def : tdRecords.getAllDerivedDefinitions("Attr")) {
-    if (!def->isAnonymous() && !curDeclScope->lookup(def->getName())) {
-      tblgen::Attribute constraint(def);
-      decls.push_back(
-          createODSNativePDLLConstraintDecl<ast::AttrConstraintDecl>(
-              constraint, convertLocToRange(def->getLoc().front()), attrTy,
-              constraint.getStorageType()));
-    }
+    if (shouldBeSkipped(def))
+      continue;
+
+    tblgen::Attribute constraint(def);
+    decls.push_back(createODSNativePDLLConstraintDecl<ast::AttrConstraintDecl>(
+        constraint, convertLocToRange(def->getLoc().front()), attrTy,
+        constraint.getStorageType()));
   }
   /// Type constraints.
   for (llvm::Record *def : tdRecords.getAllDerivedDefinitions("Type")) {
-    if (!def->isAnonymous() && !curDeclScope->lookup(def->getName())) {
-      tblgen::TypeConstraint constraint(def);
-      decls.push_back(
-          createODSNativePDLLConstraintDecl<ast::TypeConstraintDecl>(
-              constraint, convertLocToRange(def->getLoc().front()), typeTy,
-              constraint.getCPPClassName()));
-    }
+    if (shouldBeSkipped(def))
+      continue;
+
+    tblgen::TypeConstraint constraint(def);
+    decls.push_back(createODSNativePDLLConstraintDecl<ast::TypeConstraintDecl>(
+        constraint, convertLocToRange(def->getLoc().front()), typeTy,
+        constraint.getCPPClassName()));
   }
-  /// Interfaces.
+  /// OpInterfaces.
   ast::Type opTy = ast::OperationType::get(ctx);
-  for (llvm::Record *def : tdRecords.getAllDerivedDefinitions("Interface")) {
-    StringRef name = def->getName();
-    if (def->isAnonymous() || curDeclScope->lookup(name) ||
-        def->isSubClassOf("DeclareInterfaceMethods"))
+  for (llvm::Record *def : tdRecords.getAllDerivedDefinitions("OpInterface")) {
+    if (shouldBeSkipped(def))
       continue;
+
     SMRange loc = convertLocToRange(def->getLoc().front());
 
     std::string cppClassName =
         llvm::formatv("{0}::{1}", def->getValueAsString("cppNamespace"),
-                      def->getValueAsString("cppClassName"))
+                      def->getValueAsString("cppInterfaceName"))
             .str();
     std::string codeBlock =
         llvm::formatv("return ::mlir::success(llvm::isa<{0}>(self));",
@@ -913,18 +918,8 @@
 
     std::string desc =
         processAndFormatDoc(def->getValueAsString("description"));
-    if (def->isSubClassOf("OpInterface")) {
-      decls.push_back(createODSNativePDLLConstraintDecl<ast::OpConstraintDecl>(
-          name, codeBlock, loc, opTy, cppClassName, desc));
-    } else if (def->isSubClassOf("AttrInterface")) {
-      decls.push_back(
-          createODSNativePDLLConstraintDecl<ast::AttrConstraintDecl>(
-              name, codeBlock, loc, attrTy, cppClassName, desc));
-    } else if (def->isSubClassOf("TypeInterface")) {
-      decls.push_back(
-          createODSNativePDLLConstraintDecl<ast::TypeConstraintDecl>(
-              name, codeBlock, loc, typeTy, cppClassName, desc));
-    }
+    decls.push_back(createODSNativePDLLConstraintDecl<ast::OpConstraintDecl>(
+        def->getName(), codeBlock, loc, opTy, cppClassName, desc));
   }
 }
 
Index: mlir/test/mlir-pdll/Parser/include_td.pdll
===================================================================
--- mlir/test/mlir-pdll/Parser/include_td.pdll
+++ mlir/test/mlir-pdll/Parser/include_td.pdll
@@ -32,21 +32,21 @@
 // CHECK-NEXT:   CppClass: ::mlir::IntegerType
 // CHECK-NEXT: }
 
-// CHECK: UserConstraintDecl {{.*}} Name<TestAttrInterface> ResultType<Tuple<>> Code<return ::mlir::success(llvm::isa<::TestAttrInterface>(self));>
+// CHECK: UserConstraintDecl {{.*}} Name<TestAttrInterface> ResultType<Tuple<>> Code<return ::mlir::success((self.isa<TestAttrInterface>()));>
 // CHECK:  `Inputs`
 // CHECK:    `-VariableDecl {{.*}} Name<self> Type<Attr>
 // CHECK:      `Constraints`
 // CHECK:        `-AttrConstraintDecl
 
+// CHECK: UserConstraintDecl {{.*}} Name<TestTypeInterface> ResultType<Tuple<>> Code<return ::mlir::success((self.isa<TestTypeInterface>()));>
+// CHECK:  `Inputs`
+// CHECK:    `-VariableDecl {{.*}} Name<self> Type<Type>
+// CHECK:      `Constraints`
+// CHECK:        `-TypeConstraintDecl {{.*}}
+
 // CHECK: UserConstraintDecl {{.*}} Name<TestOpInterface> ResultType<Tuple<>> Code<return ::mlir::success(llvm::isa<::TestOpInterface>(self));>
 // CHECK:  `Inputs`
 // CHECK:    `-VariableDecl {{.*}} Name<self> Type<Op>
 // CHECK:      `Constraints`
 // CHECK:        `-OpConstraintDecl
 // CHECK:          `-OpNameDecl
-
-// CHECK: UserConstraintDecl {{.*}} Name<TestTypeInterface> ResultType<Tuple<>> Code<return ::mlir::success(llvm::isa<::TestTypeInterface>(self));>
-// CHECK:  `Inputs`
-// CHECK:    `-VariableDecl {{.*}} Name<self> Type<Type>
-// CHECK:      `Constraints`
-// CHECK:        `-TypeConstraintDecl {{.*}}
Index: mlir/test/mlir-tblgen/interfaces-as-constraints.td
===================================================================
--- /dev/null
+++ mlir/test/mlir-tblgen/interfaces-as-constraints.td
@@ -0,0 +1,47 @@
+// RUN: mlir-tblgen -gen-op-defs -I %S/../../include %s | FileCheck %s
+
+include "mlir/IR/OpBase.td"
+
+def Test_Dialect : Dialect {
+  let name = "test";
+}
+
+def TopLevelTypeInterface : TypeInterface<"TopLevelTypeInterface">;
+
+def TypeInterfaceInNamespace : TypeInterface<"TypeInterfaceInNamespace"> {
+	let cppNamespace = "test";
+}
+
+def TopLevelAttrInterface : AttrInterface<"TopLevelAttrInterface">;
+
+def AttrInterfaceInNamespace : AttrInterface<"AttrInterfaceInNamespace"> {
+	let cppNamespace = "test";
+}
+
+def OpUsingAllOfThose : Op<Test_Dialect, "OpUsingAllOfThose"> {
+	let arguments = (ins TopLevelAttrInterface:$attr1, AttrInterfaceInNamespace:$attr2);
+	let results = (outs TopLevelTypeInterface:$res1, TypeInterfaceInNamespace:$res2);
+}
+
+// CHECK: static ::mlir::LogicalResult {{__mlir_ods_local_type_constraint.*}}(
+// CHECK:   if (!((type.isa<TopLevelTypeInterface>()))) {
+// CHECK-NEXT:    return op->emitOpError(valueKind) << " #" << valueIndex
+// CHECK-NEXT:        << " must be TopLevelTypeInterface instance, but got " << type;
+
+// CHECK: static ::mlir::LogicalResult {{__mlir_ods_local_type_constraint.*}}(
+// CHECK:   if (!((type.isa<test::TypeInterfaceInNamespace>()))) {
+// CHECK-NEXT:    return op->emitOpError(valueKind) << " #" << valueIndex
+// CHECK-NEXT:        << " must be TypeInterfaceInNamespace instance, but got " << type;
+
+// CHECK: static ::mlir::LogicalResult {{__mlir_ods_local_attr_constraint.*}}(
+// CHECK:   if (attr && !((attr.isa<TopLevelAttrInterface>()))) {
+// CHECK-NEXT:    return op->emitOpError("attribute '") << attrName
+// CHECK-NEXT:        << "' failed to satisfy constraint: TopLevelAttrInterface instance";
+
+// CHECK: static ::mlir::LogicalResult {{__mlir_ods_local_attr_constraint.*}}(
+// CHECK:   if (attr && !((attr.isa<test::AttrInterfaceInNamespace>()))) {
+// CHECK-NEXT:    return op->emitOpError("attribute '") << attrName
+// CHECK-NEXT:        << "' failed to satisfy constraint: AttrInterfaceInNamespace instance";
+
+// CHECK: TopLevelAttrInterface OpUsingAllOfThose::attr1()
+// CHECK: test::AttrInterfaceInNamespace OpUsingAllOfThose::attr2()
Index: mlir/tools/mlir-tblgen/OpFormatGen.cpp
===================================================================
--- mlir/tools/mlir-tblgen/OpFormatGen.cpp
+++ mlir/tools/mlir-tblgen/OpFormatGen.cpp
@@ -2304,7 +2304,7 @@
       //    DeclareOpInterfaceMethods<InferTypeOpInterface>
       // and the like.
       // TODO: Add hasCppInterface check.
-      if (auto name = def.getValueAsOptionalString("cppClassName")) {
+      if (auto name = def.getValueAsOptionalString("cppInterfaceName")) {
         if (*name == "InferTypeOpInterface" &&
             def.getValueAsString("cppNamespace") == "::mlir")
           canInferResultTypes = true;