diff --git a/sql/patch_50_51_h.sql b/sql/patch_50_51_h.sql
new file mode 100644
index 0000000000000000000000000000000000000000..19637ee2c8b6dd69b9e0467cb12c0af95e0823b3
--- /dev/null
+++ b/sql/patch_50_51_h.sql
@@ -0,0 +1,13 @@
+# patch_50_51_h.sql
+#
+# title: External_db name
+#
+# description:
+# Extend db_name in external_db table to 40 characters (from 28)
+
+ALTER TABLE external_db CHANGE COLUMN db_name db_name VARCHAR(40) NOT NULL;
+
+# patch identifier
+INSERT INTO meta (species_id, meta_key, meta_value) VALUES (NULL, 'patch', 'patch_50_51_h.sql|external_db_db_name');
+
+