diff --git a/maintenance/archives/patch-ipb_anon_only.sql b/maintenance/archives/patch-ipb_anon_only.sql
index 1a534954be7..709308a238f 100644
--- a/maintenance/archives/patch-ipb_anon_only.sql
+++ b/maintenance/archives/patch-ipb_anon_only.sql
@@ -24,7 +24,7 @@ CREATE TABLE /*$wgDBprefix*/ipblocks_newunique (
   ipb_range_end tinyblob NOT NULL default '',
   
   PRIMARY KEY ipb_id (ipb_id),
-  UNIQUE INDEX ipb_address_unique (ipb_address, ipb_user, ipb_auto),
+  UNIQUE INDEX ipb_address_unique (ipb_address(255), ipb_user, ipb_auto),
   INDEX ipb_user (ipb_user),
   INDEX ipb_range (ipb_range_start(8), ipb_range_end(8)),
   INDEX ipb_timestamp (ipb_timestamp),
diff --git a/maintenance/mysql5/tables-binary.sql b/maintenance/mysql5/tables-binary.sql
index f23faaf2b60..0d5dc3fe06d 100644
--- a/maintenance/mysql5/tables-binary.sql
+++ b/maintenance/mysql5/tables-binary.sql
@@ -619,7 +619,7 @@ CREATE TABLE /*$wgDBprefix*/ipblocks (
 
   -- Unique index to support "user already blocked" messages
   -- Any new options which prevent collisions should be included
-  UNIQUE INDEX ipb_address (ipb_address, ipb_user, ipb_auto, ipb_anon_only),
+  UNIQUE INDEX ipb_address (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only),
 
   INDEX ipb_user (ipb_user),
   INDEX ipb_range (ipb_range_start(8), ipb_range_end(8)),
diff --git a/maintenance/mysql5/tables.sql b/maintenance/mysql5/tables.sql
index ec3c44a1600..ed8c68465ce 100644
--- a/maintenance/mysql5/tables.sql
+++ b/maintenance/mysql5/tables.sql
@@ -610,7 +610,7 @@ CREATE TABLE /*$wgDBprefix*/ipblocks (
 
   -- Unique index to support "user already blocked" messages
   -- Any new options which prevent collisions should be included
-  UNIQUE INDEX ipb_address (ipb_address, ipb_user, ipb_auto, ipb_anon_only),
+  UNIQUE INDEX ipb_address (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only),
 
   INDEX ipb_user (ipb_user),
   INDEX ipb_range (ipb_range_start(8), ipb_range_end(8)),
diff --git a/maintenance/tables.sql b/maintenance/tables.sql
index 651c5e47195..d2101796576 100644
--- a/maintenance/tables.sql
+++ b/maintenance/tables.sql
@@ -598,7 +598,7 @@ CREATE TABLE /*$wgDBprefix*/ipblocks (
 
   -- Unique index to support "user already blocked" messages
   -- Any new options which prevent collisions should be included
-  UNIQUE INDEX ipb_address (ipb_address, ipb_user, ipb_auto, ipb_anon_only),
+  UNIQUE INDEX ipb_address (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only),
 
   INDEX ipb_user (ipb_user),
   INDEX ipb_range (ipb_range_start(8), ipb_range_end(8)),