diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d0dc0fc3bc..a8549f644c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -97,8 +97,8 @@ stages:
 
 # Alpine Linux
 
-.alpine-3.12-amd64: &alpine_3_12_amd64_image
-  image: "$CI_REGISTRY_IMAGE:alpine-3.12-amd64"
+.alpine-3.13-amd64: &alpine_3_13_amd64_image
+  image: "$CI_REGISTRY_IMAGE:alpine-3.13-amd64"
   <<: *linux_amd64
 
 # CentOS
@@ -567,28 +567,28 @@ push:docs:
     - main@isc-projects/bind9
     - /^v9_[1-9][0-9]$/@isc-projects/bind9
 
-# Jobs for regular GCC builds on Alpine Linux 3.12 (amd64)
+# Jobs for regular GCC builds on Alpine Linux 3.13 (amd64)
 
-gcc:alpine3.12:amd64:
+gcc:alpine3.13:amd64:
   variables:
     CC: gcc
     CFLAGS: "${CFLAGS_COMMON}"
     EXTRA_CONFIGURE: "--enable-dnstap ${WITHOUT_READLINE}"
-  <<: *alpine_3_12_amd64_image
+  <<: *alpine_3_13_amd64_image
   <<: *build_job
 
-system:gcc:alpine3.12:amd64:
-  <<: *alpine_3_12_amd64_image
+system:gcc:alpine3.13:amd64:
+  <<: *alpine_3_13_amd64_image
   <<: *system_test_job
   needs:
-    - job: gcc:alpine3.12:amd64
+    - job: gcc:alpine3.13:amd64
       artifacts: true
 
-unit:gcc:alpine3.12:amd64:
-  <<: *alpine_3_12_amd64_image
+unit:gcc:alpine3.13:amd64:
+  <<: *alpine_3_13_amd64_image
   <<: *unit_test_job
   needs:
-    - job: gcc:alpine3.12:amd64
+    - job: gcc:alpine3.13:amd64
       artifacts: true
 
 # Jobs for regular GCC builds on CentOS 7 (amd64)
diff --git a/PLATFORMS.md b/PLATFORMS.md
index ec8d2138a6..25a05aa8d7 100644
--- a/PLATFORMS.md
+++ b/PLATFORMS.md
@@ -51,7 +51,7 @@ following systems:
 * Red Hat Enterprise Linux / CentOS 7, 8
 * FreeBSD 11.4, 12.2
 * OpenBSD 6.8
-* Alpine Linux 3.12
+* Alpine Linux 3.13
 
 The amd64, i386, armhf and arm64 CPU architectures are all fully supported.