diff --git a/dendrite/Dockerfile b/dendrite/Dockerfile
index 88fb75a..8827599 100644
--- a/dendrite/Dockerfile
+++ b/dendrite/Dockerfile
@@ -3,9 +3,9 @@ FROM golang:buster as builder
 ARG DEBIAN_FRONTEND=noninteractive
 COPY dendrite /dendrite
 WORKDIR /dendrite
-RUN ./build.sh
+RUN rm -rf .git && ./build.sh
 
-FROM debian:buster
+FROM debian:buster-20210111-slim
 
 COPY --from=builder /dendrite/bin/ /usr/local/bin/
 COPY --from=builder /dendrite/dendrite-config.yaml /usr/local/share/
diff --git a/dendrite/Makefile b/dendrite/Makefile
index 9f66aab..11928bb 100644
--- a/dendrite/Makefile
+++ b/dendrite/Makefile
@@ -18,4 +18,4 @@ push: git-clone
 	    --tag ${CI_REGISTRY_IMAGE}/${IMAGE}:$(VERSION) .
 
 git-clone:
-	git clone -b v${VERSION} https://github.com/matrix-org/dendrite.git
+	git clone -b v${VERSION} --depth 1 https://github.com/matrix-org/dendrite.git
diff --git a/keycloak/Dockerfile b/keycloak/Dockerfile
index 2bd7e6b..5666de2 100644
--- a/keycloak/Dockerfile
+++ b/keycloak/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster-20201209-slim
+FROM debian:buster-20210111-slim
 ADD https://curl.haxx.se/ca/cacert.pem /etc/ssl/certs/cacert.pem
 ENV CURL_CA_BUNDLE=/etc/ssl/certs/cacert.pem
 
diff --git a/minio/Dockerfile b/minio/Dockerfile
index ed5a20e..4068110 100644
--- a/minio/Dockerfile
+++ b/minio/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.12.3
+FROM alpine:3.13.0
 
 ENV MINIO_ACCESS_KEY_FILE=access_key \
     MINIO_SECRET_KEY_FILE=secret_key \
diff --git a/restic/Dockerfile b/restic/Dockerfile
index 0929433..3db116d 100644
--- a/restic/Dockerfile
+++ b/restic/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.12.3
+FROM alpine:3.13.0
 ARG VERSION
 ARG TARGETARCH
 ENV VERSION $VERSION
diff --git a/watchdog/Dockerfile b/watchdog/Dockerfile
index 16e55ba..4151b03 100644
--- a/watchdog/Dockerfile
+++ b/watchdog/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster-20201209-slim
+FROM debian:buster-20210111-slim
 ARG DEBIAN_FRONTEND=noninteractive
 ARG VERSION
 RUN apt update -qq && \