diff --git a/grc/gsm_block_tree.xml b/grc/gsm_block_tree.xml
index 69120f0..f9ff1ff 100644
--- a/grc/gsm_block_tree.xml
+++ b/grc/gsm_block_tree.xml
@@ -47,6 +47,7 @@
       <block>gsm_burst_sdcch_subslot_filter</block>
       <block>gsm_burst_fnr_filter</block>
       <block>gsm_dummy_burst_filter</block>
+      <block>gsm_uplink_downlink_splitter</block>
     </cat>
     <cat>
       <name>Utilities</name>