diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 063ccfc..65f57c4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,10 @@ name: ci
 on:
   push:
     branches: [main]
-    tags: ['*']
+    # Only semver tags (e.g. 1.4.5) trigger CI/publish — non-version tags such as
+    # `fern-generation-base--fernapi--fern-ruby-sdk` must NOT fire the publish job,
+    # otherwise they race the real version tag and re-push the same gem version.
+    tags: ['[0-9]+.[0-9]+.[0-9]+']
   pull_request:
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}