diff --git a/src/Dockerfile b/src/Dockerfile
index f8c2688..14966e0 100644
--- a/src/Dockerfile
+++ b/src/Dockerfile
@@ -17,7 +17,8 @@ ENV CERTBOT_DNS_AUTHENTICATORS \
     route53 \
     sakuracloud \
     ionos \
-    bunny
+    bunny \
+    duckdns
 
 # Needed in order to install Python packages via PIP after PEP 668 was
 # introduced, but I believe this is safe since we are in a container without
diff --git a/src/Dockerfile-alpine b/src/Dockerfile-alpine
index 8abac7a..c07f36f 100644
--- a/src/Dockerfile-alpine
+++ b/src/Dockerfile-alpine
@@ -17,7 +17,8 @@ ENV CERTBOT_DNS_AUTHENTICATORS \
     route53 \
     sakuracloud \
     ionos \
-    bunny
+    bunny \
+    duckdns
 
 # Needed in order to install Python packages via PIP after PEP 668 was
 # introduced, but I believe this is safe since we are in a container without