diff --git a/ci/Dockerfile b/ci/Dockerfile
index a68bb9a..57c8e72 100755
--- a/ci/Dockerfile
+++ b/ci/Dockerfile
@@ -58,9 +58,10 @@ RUN ./build-moos.sh -m -j"$(nproc)" && \
 # netbase provides /etc/protocols, which MOOS needs at runtime
 # (getprotobyname("tcp")). The base image lacks it, so MOOSDB would throw
 # XPCException "Could Not Get Protocol By Name" at startup without it.
+# python3 is used by the integration DB check (check_db.py).
 # Kept as a final layer so the (expensive) MOOS-IvP build stays cached.
 #-----------------------------------------------------------------------
-RUN apt-get update && apt-get install -y --no-install-recommends netbase \
+RUN apt-get update && apt-get install -y --no-install-recommends netbase python3 \
     && rm -rf /var/lib/apt/lists/*
 
 #-----------------------------------------------------------------------