diff --git a/deployment/base.sql b/deployment/base.sql
index 4ba5b33..8b912eb 100644
--- a/deployment/base.sql
+++ b/deployment/base.sql
@@ -32,7 +32,7 @@ CREATE TABLE block_log
     hex VARCHAR(128) PRIMARY KEY NOT NULL,
     find_time TIMESTAMP,
     reward BIGINT(20),
-    difficulty INT(11),
+    difficulty BIGINT(20),
     major_version INT(11),
     minor_version INT(11)
 );