diff --git a/requirements.txt b/requirements.txt
index 63c8591..14f126b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ matplotlib
 numpy<2
 pandas
 pygmt
-pygmt_helper @ git+https://github.com/ucgmsim/pygmt_helper
+pygmt_helper @ git+https://github.com/ucgmsim/pygmt_helper@cylc
 qcore @ git+https://github.com/ucgmsim/qcore@pegasus
 source_modelling @ git+https://github.com/ucgmsim/source_modelling@pegasus
 tqdm