diff --git a/docker/coturn/CHANGELOG.md b/docker/coturn/CHANGELOG.md
index 0aceb1cd..344abdbf 100644
--- a/docker/coturn/CHANGELOG.md
+++ b/docker/coturn/CHANGELOG.md
@@ -4,6 +4,16 @@ Coturn TURN server Docker image changelog
 
 
 
+## [4.5.2-r7] · 2021-11-25
+[4.5.2-r7]: /../../tree/docker/4.5.2-r7
+
+### Upgraded
+
+- [Alpine Linux] 3.15: <https://alpinelinux.org/posts/Alpine-3.15.0-released.html>
+
+
+
+
 ## [4.5.2-r6] · 2021-11-15
 [4.5.2-r6]: /../../tree/docker/4.5.2-r6
 
diff --git a/docker/coturn/CONTRIBUTING.md b/docker/coturn/CONTRIBUTING.md
index edde3e83..5b5c8968 100644
--- a/docker/coturn/CONTRIBUTING.md
+++ b/docker/coturn/CONTRIBUTING.md
@@ -49,7 +49,7 @@ To produce a new release (version tag) of `coturn/coturn` Docker image, perform
 
 3. Update [README] with the new version declared in [`Makefile`].
 
-4. Perform a `make release` command inside the`docker/coturn/` directory.
+4. Perform a `make release` command inside the `docker/coturn/` directory.
 
 
 
diff --git a/docker/coturn/Makefile b/docker/coturn/Makefile
index f4eff3f5..8b7876da 100644
--- a/docker/coturn/Makefile
+++ b/docker/coturn/Makefile
@@ -21,7 +21,7 @@ COTURN_VER ?= 4.5.2
 COTURN_MIN_VER = $(strip $(shell echo $(COTURN_VER) | cut -d '.' -f1,2))
 COTURN_MAJ_VER = $(strip $(shell echo $(COTURN_VER) | cut -d '.' -f1))
 
-BUILD_REV ?= 6
+BUILD_REV ?= 7
 
 NAMESPACES := coturn \
               ghcr.io/coturn \
diff --git a/docker/coturn/README.md b/docker/coturn/README.md
index 88ff00ce..feb636fb 100644
--- a/docker/coturn/README.md
+++ b/docker/coturn/README.md
@@ -15,8 +15,8 @@ Coturn TURN server Docker image
 
 ## Supported tags and respective `Dockerfile` links
 
-- [`4.5.2-r6`, `4.5.2-r6-debian`, `4.5.2`, `4.5.2-debian`, `4.5`, `4.5-debian`, `4`, `4-debian`, `debian`, `latest`][d1]
-- [`4.5.2-r6-alpine`, `4.5.2-alpine`, `4.5-alpine`, `4-alpine`, `alpine`][d2]
+- [`4.5.2-r7`, `4.5.2-r7-debian`, `4.5.2`, `4.5.2-debian`, `4.5`, `4.5-debian`, `4`, `4-debian`, `debian`, `latest`][d1]
+- [`4.5.2-r7-alpine`, `4.5.2-alpine`, `4.5-alpine`, `4-alpine`, `alpine`][d2]
 
 
 
diff --git a/docker/coturn/alpine/Dockerfile b/docker/coturn/alpine/Dockerfile
index f4d39276..67914bfa 100644
--- a/docker/coturn/alpine/Dockerfile
+++ b/docker/coturn/alpine/Dockerfile
@@ -2,7 +2,7 @@
 # Dockerfile of coturn/coturn:alpine Docker image.
 #
 
-ARG alpine_ver=3.14.3
+ARG alpine_ver=3.15