diff --git a/entrypoint.postgres.sh.tmpl b/entrypoint.postgres.sh.tmpl
index 8260e50..8ecc4fe 100644
--- a/entrypoint.postgres.sh.tmpl
+++ b/entrypoint.postgres.sh.tmpl
@@ -11,32 +11,34 @@ if [ -e $MIGRATION_MARKER ]; then
   exit 1
 fi
 
-DATA_VERSION=$(cat $PGDATA/PG_VERSION)
+if [ -f $PGDATA/PG_VERSION ]; then
+  DATA_VERSION=$(cat $PGDATA/PG_VERSION)
 
-if [ -n "$DATA_VERSION" -a "$PG_MAJOR" != "$DATA_VERSION" ]; then
-  echo "postgres data version $DATA_VERSION found, but need $PG_MAJOR. Starting migration"
-  echo "Installing postgres $DATA_VERSION"
-  sed -i "s/$/ $DATA_VERSION/" /etc/apt/sources.list.d/pgdg.list
-  apt-get update && apt-get install -y --no-install-recommends \
-    postgresql-$DATA_VERSION \
-    && rm -rf /var/lib/apt/lists/*
-  echo "shuffling around"
-  gosu postgres mkdir $OLDDATA $NEWDATA
-  chmod 700 $OLDDATA $NEWDATA
-  mv $PGDATA/* $OLDDATA/ || true
-  touch $MIGRATION_MARKER
-  echo "running initdb"
-  # abuse entrypoint script for initdb by making server error out
-  gosu postgres bash -c "export PGDATA=$NEWDATA ; /usr/local/bin/docker-entrypoint.sh --invalid-arg || true"
-  echo "running pg_upgrade"
-  cd /tmp
-  gosu postgres pg_upgrade --link -b /usr/lib/postgresql/$DATA_VERSION/bin -d $OLDDATA -D $NEWDATA -U $POSTGRES_USER
-  cp $OLDDATA/pg_hba.conf $NEWDATA/
-  mv $NEWDATA/* $PGDATA
-  rm -rf $OLDDATA
-  rmdir $NEWDATA
-  rm $MIGRATION_MARKER
-  echo "migration complete"
+  if [ -n "$DATA_VERSION" -a "$PG_MAJOR" != "$DATA_VERSION" ]; then
+    echo "postgres data version $DATA_VERSION found, but need $PG_MAJOR. Starting migration"
+    echo "Installing postgres $DATA_VERSION"
+    sed -i "s/$/ $DATA_VERSION/" /etc/apt/sources.list.d/pgdg.list
+    apt-get update && apt-get install -y --no-install-recommends \
+      postgresql-$DATA_VERSION \
+      && rm -rf /var/lib/apt/lists/*
+    echo "shuffling around"
+    gosu postgres mkdir $OLDDATA $NEWDATA
+    chmod 700 $OLDDATA $NEWDATA
+    mv $PGDATA/* $OLDDATA/ || true
+    touch $MIGRATION_MARKER
+    echo "running initdb"
+    # abuse entrypoint script for initdb by making server error out
+    gosu postgres bash -c "export PGDATA=$NEWDATA ; /usr/local/bin/docker-entrypoint.sh --invalid-arg || true"
+    echo "running pg_upgrade"
+    cd /tmp
+    gosu postgres pg_upgrade --link -b /usr/lib/postgresql/$DATA_VERSION/bin -d $OLDDATA -D $NEWDATA -U $POSTGRES_USER
+    cp $OLDDATA/pg_hba.conf $NEWDATA/
+    mv $NEWDATA/* $PGDATA
+    rm -rf $OLDDATA
+    rmdir $NEWDATA
+    rm $MIGRATION_MARKER
+    echo "migration complete"
+  fi
 fi
 
 /usr/local/bin/docker-entrypoint.sh postgres