diff --git a/.buildkite/longruns/pipeline.yml b/.buildkite/longruns/pipeline.yml
index 5d947b26e6..fa0174cae1 100644
--- a/.buildkite/longruns/pipeline.yml
+++ b/.buildkite/longruns/pipeline.yml
@@ -45,6 +45,9 @@ steps:
       JULIA_NUM_PRECOMPILE_TASKS: 8
       JULIA_MAX_NUM_PRECOMPILE_FILES: 50
 
+  concurrency: 1
+  concurrency_group: 'depot/climacoupler-longruns'
+
   - wait
 
   # DYAMOND AMIP: 1 day (convection resolving) - running on clima, so need to instantiate again