diff --git a/images/etherpad/Dockerfile b/images/etherpad/Dockerfile
index 32bf7ef..a929eff 100644
--- a/images/etherpad/Dockerfile
+++ b/images/etherpad/Dockerfile
@@ -32,6 +32,7 @@ ENV PYTHON /usr/bin/python3
 RUN install_packages ca-certificates curl \
 	&& mkdir -p /.npm \
 	&& bash /srv/nvm_install.sh \
+	&& [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" \
 	&& nvm install lts/erbium \
 	&& cd /srv/etherpad \
 	&& install_packages python3 make gcc g++ libc-dev libc++-dev \