diff --git a/migrations/versions/0021_add_job_metadata.py b/migrations/versions/0021_add_job_metadata.py
index fe63b294d..a72d86c23 100644
--- a/migrations/versions/0021_add_job_metadata.py
+++ b/migrations/versions/0021_add_job_metadata.py
@@ -16,7 +16,10 @@ import sqlalchemy as sa
 
 def upgrade():
     ### commands auto generated by Alembic - please adjust! ###
-    op.add_column('jobs', sa.Column('notification_count', sa.Integer(), nullable=False))
+    op.add_column('jobs', sa.Column('notification_count', sa.Integer(), nullable=True))
+    op.get_bind()
+    op.execute('update jobs set notification_count = 0')
+    op.alter_column('jobs', 'notification_count', nullable=False)
     ### end Alembic commands ###