diff --git a/src/DMAPI/tgs/v5/undefs.dm b/src/DMAPI/tgs/v5/undefs.dm
index acd19dfa64..ca49e46cdf 100644
--- a/src/DMAPI/tgs/v5/undefs.dm
+++ b/src/DMAPI/tgs/v5/undefs.dm
@@ -18,6 +18,7 @@
 
 #undef DMAPI5_PARAMETER_ACCESS_IDENTIFIER
 #undef DMAPI5_PARAMETER_CUSTOM_COMMANDS
+#undef DMAPI5_PARAMETER_TOPIC_PORT
 
 #undef DMAPI5_CHUNK
 #undef DMAPI5_CHUNK_PAYLOAD