diff --git a/migrations/versions/e5f6a7b8c9d0_add_recovery_challenges_table.py b/migrations/versions/e5f6a7b8c9d0_add_recovery_challenges_table.py
index 44084a9..2112f6b 100644
--- a/migrations/versions/e5f6a7b8c9d0_add_recovery_challenges_table.py
+++ b/migrations/versions/e5f6a7b8c9d0_add_recovery_challenges_table.py
@@ -18,6 +18,7 @@ delete expired rows without a full scan.
 """
 from alembic import op
 import sqlalchemy as sa
+from sqlalchemy.dialects.mysql import INTEGER as mysql_INTEGER
 
 
 revision = 'e5f6a7b8c9d0'
@@ -29,10 +30,10 @@ depends_on = None
 def upgrade():
     op.create_table(
         'recovery_challenges',
-        sa.Column('id',             sa.Integer(),    nullable=False, autoincrement=True),
+        sa.Column('id',             mysql_INTEGER(unsigned=True), nullable=False, autoincrement=True),
         # user_id must be INTEGER UNSIGNED to match users.id (UNSIGNED primary key).
         # MySQL 8 enforces strict type compatibility for foreign keys.
-        sa.Column('user_id',        sa.Integer(unsigned=True), nullable=False),
+        sa.Column('user_id',        mysql_INTEGER(unsigned=True), nullable=False),
         sa.Column('nonce',          sa.String(64),   nullable=False),
         sa.Column('expected_proof', sa.String(64),   nullable=False),
         sa.Column('expires_at',     sa.DateTime(),   nullable=False),