diff --git a/3.1/alpine3.19/Dockerfile b/3.1/alpine3.21/Dockerfile
similarity index 99%
rename from 3.1/alpine3.19/Dockerfile
rename to 3.1/alpine3.21/Dockerfile
index ab93cb527..587935b19 100644
--- a/3.1/alpine3.19/Dockerfile
+++ b/3.1/alpine3.21/Dockerfile
@@ -4,7 +4,7 @@
 # PLEASE DO NOT EDIT IT DIRECTLY.
 #
 
-FROM alpine:3.19
+FROM alpine:3.21
 
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.2/alpine3.19/Dockerfile b/3.2/alpine3.21/Dockerfile
similarity index 99%
rename from 3.2/alpine3.19/Dockerfile
rename to 3.2/alpine3.21/Dockerfile
index c13d2dc45..8cb6e3fd9 100644
--- a/3.2/alpine3.19/Dockerfile
+++ b/3.2/alpine3.21/Dockerfile
@@ -4,7 +4,7 @@
 # PLEASE DO NOT EDIT IT DIRECTLY.
 #
 
-FROM alpine:3.19
+FROM alpine:3.21
 
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.3/alpine3.19/Dockerfile b/3.3/alpine3.21/Dockerfile
similarity index 99%
rename from 3.3/alpine3.19/Dockerfile
rename to 3.3/alpine3.21/Dockerfile
index 0ea3669c6..cef7160d8 100644
--- a/3.3/alpine3.19/Dockerfile
+++ b/3.3/alpine3.21/Dockerfile
@@ -4,7 +4,7 @@
 # PLEASE DO NOT EDIT IT DIRECTLY.
 #
 
-FROM alpine:3.19
+FROM alpine:3.21
 
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.4-rc/alpine3.19/Dockerfile b/3.4-rc/alpine3.21/Dockerfile
similarity index 99%
rename from 3.4-rc/alpine3.19/Dockerfile
rename to 3.4-rc/alpine3.21/Dockerfile
index 31c122366..fd73efa3c 100644
--- a/3.4-rc/alpine3.19/Dockerfile
+++ b/3.4-rc/alpine3.21/Dockerfile
@@ -4,7 +4,7 @@
 # PLEASE DO NOT EDIT IT DIRECTLY.
 #
 
-FROM alpine:3.19
+FROM alpine:3.21
 
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/versions.json b/versions.json
index a79aa0fce..e61424370 100644
--- a/versions.json
+++ b/versions.json
@@ -33,8 +33,8 @@
       "slim-bookworm",
       "bullseye",
       "slim-bullseye",
-      "alpine3.20",
-      "alpine3.19"
+      "alpine3.21",
+      "alpine3.20"
     ]
   },
   "3.2": {
@@ -71,8 +71,8 @@
       "slim-bookworm",
       "bullseye",
       "slim-bullseye",
-      "alpine3.20",
-      "alpine3.19"
+      "alpine3.21",
+      "alpine3.20"
     ],
     "rust": {
       "version": "1.74.1"
@@ -141,8 +141,8 @@
       "slim-bookworm",
       "bullseye",
       "slim-bullseye",
-      "alpine3.20",
-      "alpine3.19"
+      "alpine3.21",
+      "alpine3.20"
     ],
     "rust": {
       "version": "1.74.1"
@@ -218,8 +218,8 @@
       "slim-bookworm",
       "bullseye",
       "slim-bullseye",
-      "alpine3.20",
-      "alpine3.19"
+      "alpine3.21",
+      "alpine3.20"
     ],
     "rust": {
       "version": "1.74.1"
diff --git a/versions.sh b/versions.sh
index aa5e6bc11..64bf090eb 100755
--- a/versions.sh
+++ b/versions.sh
@@ -88,8 +88,8 @@ for version in "${versions[@]}"; do
 				empty # trailing comma hack
 			| ., "slim-" + .), # https://github.com/docker-library/ruby/pull/142#issuecomment-320012893
 			(
+				"3.21",
 				"3.20",
-				"3.19",
 				empty # trailing comma hack
 			| "alpine" + .)
 		]