diff --git a/docs/Dockerfile b/docs/Dockerfile
index beab5e51a..dad6cf9c4 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -1,7 +1,7 @@
 FROM python:3.8-alpine3.13 as borgmatic
 
 COPY . /app
-RUN apk add --no-cache py3-ruamel.yaml.clib
+RUN apk add --no-cache py3-ruamel.yaml py3-ruamel.yaml.clib
 RUN pip install --no-cache /app && generate-borgmatic-config && chmod +r /etc/borgmatic/config.yaml
 RUN borgmatic --help > /command-line.txt \
     && for action in init prune create check extract export-tar mount umount restore list info borg; do \
diff --git a/scripts/run-full-tests b/scripts/run-full-tests
index 31cf3cfec..920c845e0 100755
--- a/scripts/run-full-tests
+++ b/scripts/run-full-tests
@@ -11,7 +11,7 @@
 set -e
 
 apk add --no-cache python3 py3-pip borgbackup postgresql-client mariadb-client mongodb-tools \
-    py3-ruamel.yaml.clib
+    py3-ruamel.yaml py3-ruamel.yaml.clib
 # If certain dependencies of black are available in this version of Alpine, install them.
 apk add --no-cache py3-typed-ast py3-regex || true
 python3 -m pip install --no-cache --upgrade pip==22.0.3 setuptools==60.8.1