diff --git a/check_pg_streaming_replication b/check_pg_streaming_replication
index ae746a3..d1927f8 100755
--- a/check_pg_streaming_replication
+++ b/check_pg_streaming_replication
@@ -116,14 +116,14 @@ id "$PG_USER" > /dev/null 2>&1
 
 function psql_get () {
 	sql="$1"
-	debug "Exec 'echo \"$sql\"|su - $PG_USER -c \"$PSQL_BIN -d \"$PG_DB\" -w -t -P format=unaligned\""
-	echo "$sql"|su - $PG_USER -c "$PSQL_BIN -d "$PG_DB" -w -t -P format=unaligned"
+	debug "Exec 'echo \"$sql\"|sudo -u $PG_USER $PSQL_BIN -d \"$PG_DB\" -w -t -P format=unaligned"
+	echo "$sql"|sudo -u $PG_USER $PSQL_BIN -d "$PG_DB" -w -t -P format=unaligned
 }
 
 function psql_master_get () {
 	sql="$1"
-	debug "Exec 'echo \"$sql\"|su - $PG_USER -c \"$PSQL_BIN -U $M_USER -h $M_HOST -w -p $M_PORT -d $PG_DB -t -P format=unaligned\""
-	echo "$sql"|su - $PG_USER -c "$PSQL_BIN -U $M_USER -h $M_HOST -w -p $M_PORT -d $PG_DB -t -P format=unaligned"
+	debug "Exec 'echo \"$sql\"|sudo -u $PG_USER $PSQL_BIN -U $M_USER -h $M_HOST -w -p $M_PORT -d $PG_DB -t -P format=unaligned"
+	echo "$sql"|sudo -u $PG_USER $PSQL_BIN -U $M_USER -h $M_HOST -w -p $M_PORT -d $PG_DB -t -P format=unaligned
 }
 
 function debug() {