diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5ab5704d8..02cba7a86 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -267,8 +267,7 @@ jobs:
 
   test-build-docker-images:
     if: (github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch') && needs.files-changed.outputs.docker == 'true'
-    # needs: [files-changed, build] # tmp disable
-    needs: [files-changed]
+    needs: [files-changed, build, docker-compose-tests] # tmp disable
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
diff --git a/Dockerfile.fat b/Dockerfile.fat
index 5ade20ddc..12d92a0a4 100644
--- a/Dockerfile.fat
+++ b/Dockerfile.fat
@@ -21,14 +21,14 @@ ENV DISABLE_ADDITIONAL_FEATURES=false STIRLING_PDF_DESKTOP_UI=false
 RUN ./gradlew clean build -x spotlessApply -x spotlessCheck -x test -x sonarqube
 
 # Main stage
-FROM alpine:3.20
+FROM alpine:3.22
 
 ARG VERSION_TAG
 
-# Community-Repo aktivieren
-RUN echo "http://dl-cdn.alpinelinux.org/alpine/v3.20/community" >> /etc/apk/repositories
+# Enable community repository
+RUN echo "http://dl-cdn.alpinelinux.org/alpine/v3.22/community" >> /etc/apk/repositories
 
-# Alle Pakete in einem RUN
+# Install all packages in one RUN command
 RUN --mount=type=cache,target=/var/cache/apk \
     apk upgrade --no-cache && \
     apk add --no-cache \
@@ -43,7 +43,7 @@ RUN --mount=type=cache,target=/var/cache/apk \
     openssl-dev \
     openjdk21-jre \
     ffmpeg \
-    # Doc conversion
+    # Document conversion
     gcompat \
     libc6-compat \
     libreoffice \
@@ -69,7 +69,10 @@ RUN --mount=type=cache,target=/var/cache/apk \
     py3-opencv \
     ocrmypdf \
     py3-pillow \
-    py3-pdf2image
+    py3-pdf2image \
+    # Calibre
+    calibre && \
+    apk fix --no-cache calibre
 
 # Python venv + pip packages
 RUN set -eux; \
@@ -86,8 +89,7 @@ COPY app/core/src/main/resources/static/fonts/*.ttf /usr/share/fonts/opentype/no
 # first /app directory is for the build stage, second is for the final image
 COPY --from=build /app/app/core/build/libs/*.jar app.jar
 
-
-# Verzeichnisse, Fonts, Rechte
+# Directories, fonts, permissions
 RUN set -eux; \
     mv /usr/share/tessdata /usr/share/tessdata-original && \
     mkdir -p /home/stirlingpdfuser /configs /logs /customFiles /pipeline/watchedFolders /pipeline/finishedFolders /tmp/stirling-pdf && \
@@ -99,7 +101,7 @@ RUN set -eux; \
     /home/stirlingpdfuser /scripts /usr/share/fonts/opentype/noto \
     /configs /customFiles /pipeline /tmp/stirling-pdf /app.jar
 
-# Set Environment Variables
+# Set environment variables
 ENV DISABLE_ADDITIONAL_FEATURES=true \
     VERSION_TAG=$VERSION_TAG \
     JAVA_BASE_OPTS="-XX:+UnlockExperimentalVMOptions -XX:MaxRAMPercentage=75 -XX:InitiatingHeapOccupancyPercent=20 -XX:+G1PeriodicGCInvokesConcurrent -XX:G1PeriodicGCInterval=10000 -XX:+UseStringDeduplication -XX:G1PeriodicGCSystemLoadThreshold=70" \
@@ -120,6 +122,7 @@ ENV DISABLE_ADDITIONAL_FEATURES=true \
     TMP=/tmp/stirling-pdf
 
 EXPOSE 8080/tcp
+
 # Set user and run command
 ENTRYPOINT ["tini", "--", "/scripts/init.sh"]
 CMD ["sh", "-c", "java -Dfile.encoding=UTF-8 -Djava.io.tmpdir=/tmp/stirling-pdf -jar /app.jar & /opt/venv/bin/unoserver --port 2003 --interface 127.0.0.1"]