diff --git a/.github/workflows/pr-sort.yml b/.github/workflows/pr-sort.yml
index f13b495d13..b90160c933 100644
--- a/.github/workflows/pr-sort.yml
+++ b/.github/workflows/pr-sort.yml
@@ -84,10 +84,12 @@ jobs:
         # This check avoids a bug in all-contributors-cli (issue #371) where
         # adding an existing contribution type replaces all existing contributions
         if [[ -n "${{ steps.vars.outputs.contributor }}" ]]; then
-          pixi run install
-          pixi run add ${{ steps.vars.outputs.contributor }} conference
           CONTRIBUTOR="${{ steps.vars.outputs.contributor }}"
-          # Check if contributor already has "conference" contribution (the overlap triggers the bug)
+          # Check if contributor already has "conference" contribution (the overlap triggers the bug).
+          # IMPORTANT: there must be NO unconditional `all-contributors add` before this guard.
+          # all-contributors-cli replaces a contributor's whole contributions array when re-adding an
+          # existing type, so re-adding "conference" to someone who already has it strips their other
+          # contributions. The guard below is the ONLY add path: skip when "conference" is already present.
           if ! jq -e --arg login "$CONTRIBUTOR" '.contributors[] | select(.login == $login) | .contributions | index("conference")' .all-contributorsrc > /dev/null 2>&1; then
             echo "Adding conference contribution for: $CONTRIBUTOR"
             pixi run install