diff --git a/mlir/include/mlir/IR/Dialect.h b/mlir/include/mlir/IR/Dialect.h
--- a/mlir/include/mlir/IR/Dialect.h
+++ b/mlir/include/mlir/IR/Dialect.h
@@ -149,11 +149,12 @@
 
   /// Lookup an interface for the given ID if one is registered, otherwise
   /// nullptr.
-  const DialectInterface *getRegisteredInterface(TypeID interfaceID) {
+  const DialectInterface *getRegisteredInterface(TypeID interfaceID) const {
     auto it = registeredInterfaces.find(interfaceID);
     return it != registeredInterfaces.end() ? it->getSecond().get() : nullptr;
   }
-  template <typename InterfaceT> const InterfaceT *getRegisteredInterface() {
+  template <typename InterfaceT>
+  const InterfaceT *getRegisteredInterface() const {
     return static_cast<const InterfaceT *>(
         getRegisteredInterface(InterfaceT::getInterfaceID()));
   }