diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b52412..b00c902 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [1.21.0]
+- Updated Unbound to version `1.21.0`
+
 ## [1.20.0]
 - Updated Unbound to version `1.20.0`
 
diff --git a/Dockerfile b/Dockerfile
index 0c4d783..dc49d4b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,10 @@
 FROM alpine:3.15.5
 
-ARG UNBOUND_VERSION=1.20.0
+ARG UNBOUND_VERSION=1.21.0
 
 # Install dependencies and build unbound, clean up after
 RUN apk --update add --no-cache alpine-sdk bison dns-root-hints expat-dev flex git openssl-dev && \
-    # Clone tag and build unbound source (https://github.com/NLnetLabs/unbound)
+    # Clone at given tag and build Unbound from source (https://github.com/NLnetLabs/unbound)
     git clone --depth 1 --branch "release-${UNBOUND_VERSION}" https://github.com/NLnetLabs/unbound.git /tmp/unbound && \
     cd /tmp/unbound && \
     ./configure && \