Rails / Paranoia Gem: Undefined local variable or method `acts_as_paranoid'

Question

Environment:

• gem "paranoia", "~> 2.0" (https://github.com/radar/paranoia);

• rails 4.1.8;

• sqlite3;

When I did Listing.find(1) in rails console, it sends me such error message:

undefined local variable or method `acts_as_paranoid' for Listing (call 'Listing.connection' to establish a connection):Class

If I remove the acts_as_paranoid in Listing model, the query can go through.

Other than in the Rails console, the Paranoia gem itself works well.

Did anyone meet this issue before?