diff --git a/clientapi/auth/storage/accounts/postgres/storage.go b/clientapi/auth/storage/accounts/postgres/storage.go
index d7a753fb6..4be5dca94 100644
--- a/clientapi/auth/storage/accounts/postgres/storage.go
+++ b/clientapi/auth/storage/accounts/postgres/storage.go
@@ -138,7 +138,7 @@ func (d *Database) CreateGuestAccount(ctx context.Context) (acc *authtypes.Accou
 
 // CreateAccount makes a new account with the given login name and password, and creates an empty profile
 // for this account. If no password is supplied, the account will be a passwordless account. If the
-// account already exists, it will return nil, nil.
+// account already exists, it will return nil, ErrUserExists.
 func (d *Database) CreateAccount(
 	ctx context.Context, localpart, plaintextPassword, appserviceID string,
 ) (acc *authtypes.Account, err error) {