sqlcipher how to import a sqlite3 database

I have dumped a sqlite3 database into a .sql file. Afterwards I have import the files like this:

cat databasedump.sql | sqlcipher encrypted_database

Then I've opened the encrypted database and set the key with:

pragma key="12345"

then I close the database and reopen it, it's still not encrypted.

How can I load the dump in the database and encrypt it?