Fix #3603
diff --git a/user_guide_src/source/libraries/sessions.rst b/user_guide_src/source/libraries/sessions.rst
index 57c2585..9fc3324 100644
--- a/user_guide_src/source/libraries/sessions.rst
+++ b/user_guide_src/source/libraries/sessions.rst
@@ -596,7 +596,7 @@
 		`id` varchar(40) NOT NULL,
 		`ip_address` varchar(45) NOT NULL,
 		`timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
-		`data` blob DEFAULT '' NOT NULL,
+		`data` blob NOT NULL,
 		PRIMARY KEY (id),
 		KEY `ci_sessions_timestamp` (`timestamp`)
 	);