pg_restore: [archiver] did not find magic string in file header

I'm using PostgreSQL 9.1 and want to restore backup files generated with pg_dump: sudo pg_dump -h 127.0.0.1 -U postgres --clean --inserts -E UTF8 -f out.sql database_name This command generates a valid sql file that starts with droping any existing database objects, then generates all tables, indizes, sequences and so on, and finally inserts data. When I try to restore the generated backup file with: (line breaks added for display purposes only) sudo pg_restore -d database_name -h 127.0.0.1 -U postgres --format=c --clean --create out.sql it fails and prints: pg_restore: [archiver] did not find magic string in file header What is the reason for that?