diff --git a/vars/dockerBuild.groovy b/vars/dockerBuild.groovy
index f7ece8cb..7cafb302 100644
--- a/vars/dockerBuild.groovy
+++ b/vars/dockerBuild.groovy
@@ -25,7 +25,7 @@ def call(body) {
   // evaluate the body block, and collect configuration into the object
   def config = body
 
-  def tags = config.get('tags',['latest'])
+  def tags = config.get('tags',['latest']).unique()
   def dockerRepo = "${config.repo}/${config.image}"
   def buildDir = config.get('dir', '.')
   def dockerfile = config.get('dockerfile', 'Dockerfile')
diff --git a/vars/dockerBuildx.groovy b/vars/dockerBuildx.groovy
index f72eb4f2..4596dd40 100644
--- a/vars/dockerBuildx.groovy
+++ b/vars/dockerBuildx.groovy
@@ -30,7 +30,7 @@ def call(body) {
   // evaluate the body block, and collect configuration into the object
   def config = body
 
-  def tags = config.get('tags',['latest'])
+  def tags = config.get('tags',['latest']).unique()
   def dockerRepo = "${config.repo}/${config.image}"
   def buildDir = config.get('dir', '.')
   def dockerfile = config.get('dockerfile', 'Dockerfile')