diff --git a/contrib/ast-db-manage/config/versions/581a4264e537_adding_extensions.py b/contrib/ast-db-manage/config/versions/581a4264e537_adding_extensions.py
index ecee0e04efdb8b17ec3c8d74b45dede3aae9d4fc..415f5bc25c4a1254785a7af6bb0c61aa16755541 100755
--- a/contrib/ast-db-manage/config/versions/581a4264e537_adding_extensions.py
+++ b/contrib/ast-db-manage/config/versions/581a4264e537_adding_extensions.py
@@ -31,20 +31,18 @@ down_revision = '43956d550a44'
 from alembic import op
 import sqlalchemy as sa
 
-
 def upgrade():
     op.create_table(
         'extensions',
         sa.Column('id', sa.BigInteger, primary_key=True, nullable=False,
                   unique=True, autoincrement=True),
-        sa.Column('context', sa.String(40), primary_key=True, nullable=False),
-        sa.Column('exten', sa.String(40), primary_key=True, nullable=False),
-        sa.Column('priority', sa.Integer, primary_key=True, nullable=False,
-                  autoincrement=True),
+        sa.Column('context', sa.String(40), nullable=False),
+        sa.Column('exten', sa.String(40), nullable=False),
+        sa.Column('priority', sa.Integer, nullable=False),
         sa.Column('app', sa.String(40), nullable=False),
         sa.Column('appdata', sa.String(256), nullable=False),
+        sa.UniqueConstraint('context', 'exten', 'priority')
     )
 
-
 def downgrade():
     op.drop_table('extensions')