diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d27d7283a9bdfd5455d6eb96924d57fd2f71eace..b79d310232f80d2893759d2808ff1db2274c4f6f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -215,6 +215,8 @@ test:linux:amd64:valgrind:
   dependencies: []
   only:
     - branches@knot/knot-resolver  # do not trigger job for forks
+  except:
+    - master
   script:
     - export TESTDIR="/var/tmp/respdiff-jobs/$(git rev-parse --short HEAD)-gitlab/$RESPDIFF_TEST"
     - >