diff --git a/.github/workflows/unit_tests_ubuntu.yml b/.github/workflows/unit_tests_ubuntu.yml
index 771cc10..6432b51 100644
--- a/.github/workflows/unit_tests_ubuntu.yml
+++ b/.github/workflows/unit_tests_ubuntu.yml
@@ -4,7 +4,7 @@
 name: CI run Ubuntu
 
 on:
-  pull_request:
+  pull_request: [3.3dev]
     paths-ignore:
       - 'utils/**'
       - 'doc/**'