diff --git a/Dockerfile b/Dockerfile
index 4dc0df9..786b6a2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,7 @@ ENV PG_CONFDIR="/etc/postgresql/${PG_VERSION}/main" \
 RUN wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
  && echo 'deb http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main' > /etc/apt/sources.list.d/pgdg.list \
  && apt-get update \
- && apt-get install -y postgresql-${PG_VERSION} postgresql-client-${PG_VERSION} postgresql-contrib-${PG_VERSION} \
+ && DEBIAN_FRONTEND=noninteractive apt-get install -y postgresql-${PG_VERSION} postgresql-client-${PG_VERSION} postgresql-contrib-${PG_VERSION} \
  && rm -rf ${PG_HOME} \
  && rm -rf /var/lib/apt/lists/*
 
diff --git a/entrypoint.sh b/entrypoint.sh
index ab65d7b..94da299 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -165,7 +165,7 @@ if [[ -n ${PG_OLD_VERSION} ]]; then
 
   echo "Installing postgresql-${PG_OLD_VERSION}..."
   apt-get update
-  apt-get install postgresql-${PG_OLD_VERSION} postgresql-client-${PG_OLD_VERSION}
+  DEBIAN_FRONTEND=noninteractive apt-get install postgresql-${PG_OLD_VERSION} postgresql-client-${PG_OLD_VERSION}
   rm -rf /var/lib/apt/lists/*
 
   # migrate ${PG_OLD_VERSION} data