diff --git a/matrix-synapse/values.yaml b/matrix-synapse/values.yaml
index 71505eb..fc1114a 100644
--- a/matrix-synapse/values.yaml
+++ b/matrix-synapse/values.yaml
@@ -793,7 +793,7 @@ volumePermissions:
   image:
     registry: docker.io
     repository: library/alpine
-    tag: 3.21.2
+    tag: 3.21.3
     pullPolicy: Always
 
     ## Optionally specify an array of imagePullSecrets.