diff --git a/client/Dockerfile b/client/Dockerfile
index d8feefe..9e28411 100644
--- a/client/Dockerfile
+++ b/client/Dockerfile
@@ -4,10 +4,10 @@ FROM golang:1.12-alpine AS builder
 
 ENV MOLE_VERSION=0.4.0
 
-RUN apk add --no-cache git curl tar
+RUN apk add --no-cache git=2.22.0-r0 curl=7.66.0-r0 tar=1.32-r0
 
 RUN mkdir /app
-RUN curl -L https://github.com/davrodpin/mole/archive/v${MOLE_VERSION}.tar.gz | tar zx -C /app
+RUN curl -L "https://github.com/davrodpin/mole/archive/v${MOLE_VERSION}.tar.gz" | tar zx -C /app
 WORKDIR /app/mole-${MOLE_VERSION}
 
 # Download dependencies so they can be cached
@@ -16,17 +16,18 @@ RUN go mod download
 # Build static
 ARG GOARCH=amd64
 ENV CGO_ENABLED=0 GOOS=linux
-RUN go build -a -ldflags '-X main.version=${MOLE_VERSION}-dockamole' -installsuffix nocgo -o /bin/mole github.com/davrodpin/mole/cmd/mole
+RUN go build -a -ldflags "-X main.version=${MOLE_VERSION}-dockamole" -installsuffix nocgo -o /bin/mole github.com/davrodpin/mole/cmd/mole
 
 # Build client image using target arch
-FROM ${REPO}/alpine
+FROM multiarch/qemu-user-static:4.1.0-1 as qemu-user-static
+FROM ${REPO}/alpine:3.9
 
 # Make multiarch capable
-COPY --from=multiarch/qemu-user-static /usr/bin/qemu-* /usr/bin/
+COPY --from=qemu-user-static /usr/bin/qemu-* /usr/bin/
 # Copy mole from builder
 COPY --from=builder /bin/mole /usr/bin/mole
 
-RUN apk --no-cache add bash openssh-client
+RUN apk --no-cache add bash=4.4.19-r1 openssh-client=7.9_p1-r6
 
 RUN mkdir /mole
 RUN adduser -S -h /mole mole
@@ -38,6 +39,7 @@ RUN touch /mole/.ssh/config
 # Make a volume to persist keys
 VOLUME /mole/.ssh
 
+# Generate known hosts on first connect
 ENV GEN_KNOWN_HOSTS=1
 
 COPY ./start.sh ./
diff --git a/server/Dockerfile b/server/Dockerfile
index 3e8a53c..f9e55a6 100644
--- a/server/Dockerfile
+++ b/server/Dockerfile
@@ -1,10 +1,11 @@
 ARG REPO=library
-FROM ${REPO}/alpine
+FROM multiarch/qemu-user-static:4.1.0-1 as qemu-user-static
+FROM ${REPO}/alpine:3.9
 
-COPY --from=multiarch/qemu-user-static /usr/bin/qemu-* /usr/bin/
+COPY --from=qemu-user-static /usr/bin/qemu-* /usr/bin/
 
 # Install SSH and set up basic config
-RUN apk add openssh-server augeas
+RUN apk add --no-cache openssh-server=7.9_p1-r6 augeas=1.11.0-r0
 
 # Create sshd configs
 RUN mkdir /var/run/sshd