diff --git a/.github/workflows/monolithic-casa.yml b/.github/workflows/monolithic-casa.yml
index 1966bcd..8141055 100644
--- a/.github/workflows/monolithic-casa.yml
+++ b/.github/workflows/monolithic-casa.yml
@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 env:
   CASA_RELEASE: casa-6.7.0-31-py3.10.el8
 
diff --git a/.github/workflows/pythonapp.yml b/.github/workflows/pythonapp.yml
index 2f05b9e..c04e83e 100644
--- a/.github/workflows/pythonapp.yml
+++ b/.github/workflows/pythonapp.yml
@@ -9,6 +9,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build: