diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c0b49fe0..270c4626 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -117,6 +117,16 @@ get_data:
     - ln -s "${LOCAL_DATA_PATH}/sim_output" "${DETECTOR_CONFIG}/sim_output"
     - ln -s "../results" "${DETECTOR_CONFIG}/results"
     - mkdir -p "$SNAKEMAKE_OUTPUT_CACHE"
+    - stat -c %x,%z,%n *
+    # GitLab CI will have new timestamps in each job, which messes with
+    # Snakemake outdated file detection.  This resets file timestamps according
+    # to latest modification in git.
+    - |
+      for file in $(git ls-files); do
+        time="$(git log --pretty=format:%cd -n 1 --date=format:%Y%m%d%H%M.%S --date-order -- "$file")"
+        touch -m -t "$time" "$file"
+      done
+    - stat -c %x,%z,%n *
     - ls -lrtha
   retry:
     max: 2