diff --git a/coverage2sql/migrations/versions/52dfb338f74e_add_coverages_table.py b/coverage2sql/migrations/versions/52dfb338f74e_add_coverages_table.py
index c352d22..7b35cfe 100644
--- a/coverage2sql/migrations/versions/52dfb338f74e_add_coverages_table.py
+++ b/coverage2sql/migrations/versions/52dfb338f74e_add_coverages_table.py
@@ -28,4 +28,4 @@ def upgrade():
 
 
 def downgrade():
-    pass
+    raise NotImplementedError()