diff --git a/Dockerfile b/Dockerfile
index 22aae93..2ad242c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,9 @@ FROM --platform=$BUILDPLATFORM rust:1-buster AS rust-sources-downloader
 ARG ZKGROUP_VERSION
 
 RUN cd /tmp/ && git clone https://github.com/signalapp/zkgroup.git zkgroup-${ZKGROUP_VERSION}
-RUN cd /tmp/zkgroup-${ZKGROUP_VERSION} && cargo fetch
+RUN cd /tmp/zkgroup-${ZKGROUP_VERSION} \
+	&& mkdir -p /tmp/zkgroup-${ZKGROUP_VERSION}/.cargo \
+	&& cargo vendor > /tmp/zkgroup-${ZKGROUP_VERSION}/.cargo/config
 
 
 FROM golang:1.13-buster AS buildcontainer
@@ -54,6 +56,8 @@ RUN ls /tmp/signal-cli/lib/zkgroup-java-${ZKGROUP_VERSION}.jar || (echo "\n\nzkg
 
 COPY --from=rust-sources-downloader /tmp/zkgroup-${ZKGROUP_VERSION} /tmp/zkgroup-${ZKGROUP_VERSION} 
 
+ENV CARGO_NET_OFFLINE true
+
 RUN	cd /tmp/zkgroup-${ZKGROUP_VERSION} \
 	&& make libzkgroup \
 	&& ln -s /tmp/zkgroup-${ZKGROUP_VERSION} /tmp/zkgroup