diff --git a/test_communication/CMakeLists.txt b/test_communication/CMakeLists.txt
index 6fda4397..09d0e756 100644
--- a/test_communication/CMakeLists.txt
+++ b/test_communication/CMakeLists.txt
@@ -41,20 +41,18 @@ if(BUILD_TESTING)
   foreach(interface_file ${interface_files})
     get_filename_component(interface_ns "${interface_file}" DIRECTORY)
     get_filename_component(interface_ns "${interface_ns}" NAME)
-    string_ends_with("${interface_file}" ".msg" is_message)
-    if(is_message AND interface_ns STREQUAL "msg")
-      list(APPEND message_files "${interface_file}")
+    # Only process IDL interfaces
+    string_ends_with("${interface_file}" ".idl" is_idl)
+    if(NOT is_idl)
       continue()
     endif()
-    string_ends_with("${interface_file}" ".srv" is_service)
-    if(is_service AND interface_ns STREQUAL "srv")
+    # Decide category based on interface_ns
+    if(interface_ns STREQUAL "msg")
+      list(APPEND message_files "${interface_file}")
+    elseif(interface_ns STREQUAL "srv")
       list(APPEND service_files "${interface_file}")
-      continue()
-    endif()
-    string_ends_with("${interface_file}" ".idl" is_action)
-    if(is_action AND interface_ns STREQUAL "action")
+    elseif(interface_ns STREQUAL "action")
       list(APPEND action_files "${interface_file}")
-      continue()
     endif()
   endforeach()