diff --git a/migrations/021.do.sucessful-http-retrieval-stats.sql b/migrations/021.do.sucessful-http-retrieval-stats.sql
index e2bb008..a95de3e 100644
--- a/migrations/021.do.sucessful-http-retrieval-stats.sql
+++ b/migrations/021.do.sucessful-http-retrieval-stats.sql
@@ -1 +1 @@
-ALTER TABLE retrieval_stats ADD COLUMN IF NOT EXISTS successful_http INT NOT NULL DEFAULT 0;
+ALTER TABLE retrieval_stats ADD COLUMN IF NOT EXISTS successful_http INT;