diff --git a/mlir/include/mlir/Support/DebugAction.h b/mlir/include/mlir/Support/DebugAction.h
--- a/mlir/include/mlir/Support/DebugAction.h
+++ b/mlir/include/mlir/Support/DebugAction.h
@@ -205,8 +205,7 @@
 
     /// Provide classof to allow casting between handler types.
     static bool classof(const DebugActionManager::HandlerBase *handler) {
-      return handler->getHandlerID() ==
-             TypeID::get<DebugAction<ParameterTs...>::Handler>();
+      return handler->getHandlerID() == TypeID::get<Handler>();
     }
   };
 
diff --git a/mlir/unittests/CMakeLists.txt b/mlir/unittests/CMakeLists.txt
--- a/mlir/unittests/CMakeLists.txt
+++ b/mlir/unittests/CMakeLists.txt
@@ -11,6 +11,7 @@
 add_subdirectory(Interfaces)
 add_subdirectory(IR)
 add_subdirectory(Pass)
+add_subdirectory(Support)
 add_subdirectory(Rewrite)
 add_subdirectory(TableGen)
 add_subdirectory(Transforms)
diff --git a/mlir/unittests/Support/CMakeLists.txt b/mlir/unittests/Support/CMakeLists.txt
--- a/mlir/unittests/Support/CMakeLists.txt
+++ b/mlir/unittests/Support/CMakeLists.txt
@@ -7,4 +7,4 @@
 )
 
 target_link_libraries(MLIRSupportTests
-  PRIVATE MLIRSupportIndentedOstream MLIRSupport)
+  PRIVATE MLIRSupport)