diff --git a/gitflow-common b/gitflow-common
index 2fbd8ec..c96b845 100644
--- a/gitflow-common
+++ b/gitflow-common
@@ -42,6 +42,7 @@
 LOCAL_BRANCHES=$(git branch | sed 's/^[* ] //')
 REMOTE_BRANCHES=$(git branch -r | sed 's/^[* ] //')
 ALL_BRANCHES="$LOCAL_BRANCHES $REMOTE_BRANCHES"
+ALL_TAGS=$(git tag)
 
 #
 # resolve_nameprefix
@@ -141,6 +142,12 @@
 	fi
 }
 
+gitflow_require_tag_absent() {
+	if has $1 $ALL_TAGS; then
+		die "Tag '$1' already exists. Pick another name."
+	fi
+}
+
 #
 # gitflow_test_branches_equal()
 #