diff --git a/rosidl_typesupport_c/cmake/rosidl_typesupport_c_generate_interfaces.cmake b/rosidl_typesupport_c/cmake/rosidl_typesupport_c_generate_interfaces.cmake
index 3dd623d8..d9ced288 100644
--- a/rosidl_typesupport_c/cmake/rosidl_typesupport_c_generate_interfaces.cmake
+++ b/rosidl_typesupport_c/cmake/rosidl_typesupport_c_generate_interfaces.cmake
@@ -12,6 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+if(NOT rosidl_generator_c_FOUND)
+  message(FATAL_ERROR
+    "Executing rosidl_typesupport_c extension point when rosidl_generator_c wasn't found."
+    "Make sure rosidl_generator_c is installed.")
+endif()
+
 set(_output_path
   "${CMAKE_CURRENT_BINARY_DIR}/rosidl_typesupport_c/${PROJECT_NAME}")
 set(_generated_sources "")
diff --git a/rosidl_typesupport_c/rosidl_typesupport_c-extras.cmake.in b/rosidl_typesupport_c/rosidl_typesupport_c-extras.cmake.in
index b31f7b75..0c63524f 100644
--- a/rosidl_typesupport_c/rosidl_typesupport_c-extras.cmake.in
+++ b/rosidl_typesupport_c/rosidl_typesupport_c-extras.cmake.in
@@ -10,9 +10,9 @@ find_package(ament_cmake_core QUIET REQUIRED)
 get_used_typesupports(_typesupports "rosidl_typesupport_c")
 
 # Make sure extension points are registered in order
-find_package(rosidl_generator_c QUIET REQUIRED)
+find_package(rosidl_generator_c QUIET)
 foreach(_typesupport ${_typesupports})
-  find_package(${_typesupport} QUIET REQUIRED)
+  find_package(${_typesupport} QUIET)
 endforeach()
 
 ament_register_extension(
diff --git a/rosidl_typesupport_cpp/cmake/rosidl_typesupport_cpp_generate_interfaces.cmake b/rosidl_typesupport_cpp/cmake/rosidl_typesupport_cpp_generate_interfaces.cmake
index cf26f206..8f7bd248 100644
--- a/rosidl_typesupport_cpp/cmake/rosidl_typesupport_cpp_generate_interfaces.cmake
+++ b/rosidl_typesupport_cpp/cmake/rosidl_typesupport_cpp_generate_interfaces.cmake
@@ -12,6 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+if(NOT rosidl_generator_cpp_FOUND)
+  message(FATAL_ERROR
+    "Executing rosidl_typesupport_cpp extension point when rosidl_generator_cpp wasn't found."
+    "Make sure rosidl_generator_cpp is installed.")
+endif()
+
 set(_output_path
   "${CMAKE_CURRENT_BINARY_DIR}/rosidl_typesupport_cpp/${PROJECT_NAME}")
 set(_generated_sources "")
diff --git a/rosidl_typesupport_cpp/rosidl_typesupport_cpp-extras.cmake.in b/rosidl_typesupport_cpp/rosidl_typesupport_cpp-extras.cmake.in
index 93babb11..afcbf84f 100644
--- a/rosidl_typesupport_cpp/rosidl_typesupport_cpp-extras.cmake.in
+++ b/rosidl_typesupport_cpp/rosidl_typesupport_cpp-extras.cmake.in
@@ -10,9 +10,9 @@ find_package(rosidl_typesupport_c QUIET REQUIRED)
 get_used_typesupports(_typesupports "rosidl_typesupport_cpp")
 
 # Make sure extension points are registered in order
-find_package(rosidl_generator_cpp QUIET REQUIRED)
+find_package(rosidl_generator_cpp QUIET)
 foreach(_typesupport ${_typesupports})
-  find_package(${_typesupport} QUIET REQUIRED)
+  find_package(${_typesupport} QUIET)
 endforeach()
 
 ament_register_extension(