diff --git a/README.md b/README.md
index 392ac0e..d19575e 100644
--- a/README.md
+++ b/README.md
@@ -182,7 +182,7 @@ Derives the next version for the pushed branch and pushes it as a tag on the tri
 
 If the stable tag of a line exists (`v2.4.0` after the release), the next patch of that line is used (`v2.4.1-beta.0`, `v2.4.1-dev.…`).
 
-Only the commit that triggered the pipeline is tagged; if the branch moved on, the step exits without a tag and the newer pipeline takes over. A commit that already carries a `v*` tag is not tagged again, so a re-run does not build twice.
+Only the commit that triggered the pipeline is tagged; if the branch moved on, the step exits without a tag and the newer pipeline takes over. A commit that already carries a tag of the same kind (dev, beta or stable) is not tagged again, so a re-run does not build twice; a dev tag does not block the beta tag after a fast-forward merge.
 
 Settings:
 
diff --git a/woodpecker/bump/bump.sh b/woodpecker/bump/bump.sh
index ff88bbe..2fac881 100755
--- a/woodpecker/bump/bump.sh
+++ b/woodpecker/bump/bump.sh
@@ -45,12 +45,6 @@ if [[ $head != "$SHA" ]]; then
 fi
 git checkout --quiet "$SHA"
 
-# A re-run must not produce a second tag and a second build for the same commit.
-if existing=$(git tag --points-at HEAD 'v*' | head -n 1) && [[ -n $existing ]]; then
-  echo "bump: ${SHA:0:8} already carries $existing, nothing to do"
-  exit 0
-fi
-
 tag_exists() { git rev-parse -q --verify "refs/tags/v$1" >/dev/null; }
 
 # "2.4" or "v2.4.1" -> "2.4.0" / "2.4.1"; fails for anything else
@@ -150,6 +144,20 @@ case $BRANCH in
 esac
 TAG=v$VERSION
 
+# A re-run must not produce a second tag and a second build for the same commit.
+# Only tags of the same kind count: a dev tag on a commit that is then merged
+# fast-forward into a release branch must not block its beta tag.
+case $TAG in
+  *-dev.*) same_kind='^v[0-9]+\.[0-9]+\.[0-9]+-dev\.' ;;
+  *-beta.*) same_kind='^v[0-9]+\.[0-9]+\.[0-9]+-beta\.' ;;
+  *) same_kind='^v[0-9]+\.[0-9]+\.[0-9]+$' ;;
+esac
+existing=$(git tag --points-at HEAD 'v*' | grep -E "$same_kind" | head -n 1 || true)
+if [[ -n $existing ]]; then
+  echo "bump: ${SHA:0:8} already carries $existing, nothing to do"
+  exit 0
+fi
+
 git tag "$TAG"
 if ! git push --quiet origin "refs/tags/$TAG"; then
   echo "bump: push of $TAG rejected, the newer pipeline bumps"