diff --git a/contrib/pg_upgrade/test.sh b/contrib/pg_upgrade/test.sh
index 2dc737a2ec9..5fdf8057f1e 100644
--- a/contrib/pg_upgrade/test.sh
+++ b/contrib/pg_upgrade/test.sh
@@ -21,6 +21,10 @@ unset MAKELEVEL
 # authentication configuration.
 standard_initdb() {
 	"$1" -N
+	if [ -n "$TEMP_CONFIG" -a -r "$TEMP_CONFIG" ]
+	then
+		cat "$TEMP_CONFIG" >> "$PGDATA/postgresql.conf"
+	fi
 	../../src/test/regress/pg_regress --config-auth "$PGDATA"
 }