diff --git a/core/modules/comment/comment.install b/core/modules/comment/comment.install
index 0a147b5..8a50142 100644
--- a/core/modules/comment/comment.install
+++ b/core/modules/comment/comment.install
@@ -105,12 +105,14 @@ function comment_schema() {
       ),
       'nid' => array(
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
         'description' => 'The {node}.nid to which this comment is a reply.',
       ),
       'uid' => array(
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
         'description' => 'The {users}.uid who authored the comment. If set to 0, this comment was created by an anonymous user.',
@@ -234,6 +236,7 @@ function comment_schema() {
       ),
       'last_comment_uid' => array(
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
         'description' => 'The user ID of the latest author to post a comment on this node, from {comment}.uid.',
@@ -317,6 +320,35 @@ function comment_update_8001() {
 }
 
 /**
+ * Make *id fields unsigned.
+ */
+function comment_update_8002() {
+  $schema = drupal_get_schema('comment', TRUE);
+  db_drop_index('comment', 'comment_num_new');
+  db_drop_index('comment', 'comment_nid_langcode');
+  db_change_field('comment', 'nid', 'nid', $schema['fields']['nid'],
+    array('indexes' => array(
+      'comment_num_new' => $schema['indexes']['comment_num_new'],
+      'comment_nid_langcode' => $schema['indexes']['comment_nid_langcode'],
+    ))
+  );
+  db_drop_index('comment', 'comment_uid');
+  db_change_field('comment', 'uid', 'uid', $schema['fields']['uid'],
+    array('indexes' => array(
+      'comment_uid' => $schema['indexes']['comment_uid'],
+    ))
+  );
+
+  $schema = drupal_get_schema('node_comment_statistics', TRUE);
+  db_drop_index('node_comment_statistics', 'last_comment_uid');
+  db_change_field('node_comment_statistics', 'last_comment_uid', 'last_comment_uid', $schema['fields']['last_comment_uid'],
+    array('indexes' => array(
+      'last_comment_uid' => $schema['indexes']['last_comment_uid'],
+    ))
+  );
+}
+
+/**
  * @} End of "addtogroup updates-7.x-to-8.x".
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/dblog/dblog.install b/core/modules/dblog/dblog.install
index 919bab3..c1bcdaf 100644
--- a/core/modules/dblog/dblog.install
+++ b/core/modules/dblog/dblog.install
@@ -19,6 +19,7 @@ function dblog_schema() {
       ),
       'uid' => array(
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
         'description' => 'The {users}.uid of the user who triggered the event.',
@@ -107,6 +108,19 @@ function dblog_update_8000() {
 }
 
 /**
+ * Make *id fields unsigned.
+ */
+function dblog_update_8001() {
+  $schema = drupal_get_schema('watchdog', TRUE);
+  db_drop_index('watchdog', 'uid');
+  db_change_field('watchdog', 'uid', 'uid', $schema['fields']['uid'],
+    array('indexes' => array(
+      'uid' => $schema['indexes']['uid'],
+    ))
+  );
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x"
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/node/node.install b/core/modules/node/node.install
index 5727129..409b922 100644
--- a/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -57,6 +57,7 @@ function node_schema() {
       'uid' => array(
         'description' => 'The {users}.uid that owns this node; initially, this is the user that created it.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
@@ -215,6 +216,7 @@ function node_schema() {
       'uid' => array(
         'description' => 'The {users}.uid that created this version.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
@@ -410,12 +412,14 @@ function node_schema() {
       'uid' => array(
         'description' => 'The {users}.uid that read the {node} nid.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
       'nid' => array(
         'description' => 'The {node}.nid that was read.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
@@ -601,6 +605,37 @@ function node_update_8004() {
 }
 
 /**
+ * Make *id fields unsigned.
+ */
+function node_update_8005() {
+  $schema = drupal_get_schema('node', TRUE);
+  db_drop_index('node', 'uid');
+  db_change_field('node', 'uid', 'uid', $schema['fields']['uid'],
+    array('indexes' => array(
+      'uid' => $schema['indexes']['uid'],
+    ))
+  );
+
+  $schema = drupal_get_schema('node_revision', TRUE);
+  db_drop_index('node_revision', 'uid');
+  db_change_field('node_revision', 'uid', 'uid', $schema['fields']['uid'],
+    array('indexes' => array(
+      'uid' => $schema['indexes']['uid'],
+    ))
+  );
+
+  $schema = drupal_get_schema('history', TRUE);
+  db_drop_primary_key('history');
+  db_change_field('history', 'uid', 'uid', $schema['fields']['uid']);
+  db_drop_index('history', 'nid');
+  db_change_field('history', 'nid', 'nid', $schema['fields']['nid'],
+    array('primary key' => $schema['primary key'], 'indexes' => array(
+      'nid' => $schema['indexes']['nid'],
+    ))
+  );
+}
+
+/**
  * @} End of "addtogroup updates-7.x-to-8.x"
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/statistics/statistics.install b/core/modules/statistics/statistics.install
index 97c5518..2674f46 100644
--- a/core/modules/statistics/statistics.install
+++ b/core/modules/statistics/statistics.install
@@ -88,6 +88,7 @@ function statistics_schema() {
       'nid' => array(
         'description' => 'The {node}.nid for these statistics.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
@@ -136,3 +137,14 @@ function statistics_update_8000() {
     'statistics_block_top_last_num' => 'block.popular.top_recent_limit',
   ));
 }
+
+/**
+ * Make *id fields unsigned.
+ */
+function statistics_update_8001() {
+  $schema = drupal_get_schema('node_counter', TRUE);
+  db_drop_primary_key('node_counter');
+  db_change_field('node_counter', 'nid', 'nid', $schema['fields']['nid'],
+    array('primary key' => $schema['primary key'])
+  );
+}
diff --git a/core/modules/tracker/tracker.install b/core/modules/tracker/tracker.install
index 64dd8c4..a6f1ac4 100644
--- a/core/modules/tracker/tracker.install
+++ b/core/modules/tracker/tracker.install
@@ -79,6 +79,7 @@ function tracker_schema() {
       'uid' => array(
         'description' => 'The {users}.uid of the node author or commenter.',
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
       ),
@@ -132,6 +133,20 @@ function tracker_update_8000() {
 }
 
 /**
+ * Make *id fields unsigned.
+ */
+function tracker_update_8001() {
+  $schema = drupal_get_schema('tracker_user', TRUE);
+  db_drop_primary_key('tracker_user');
+  db_drop_index('tracker_user', 'tracker');
+  db_change_field('tracker_user', 'uid', 'uid', $schema['fields']['uid'],
+    array('primary key' => $schema['primary key'], 'indexes' => array(
+      'tracker' => $schema['indexes']['tracker'],
+    ))
+  );
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x".
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/user/user.install b/core/modules/user/user.install
index abb985b..305af26 100644
--- a/core/modules/user/user.install
+++ b/core/modules/user/user.install
@@ -20,6 +20,7 @@ function user_schema() {
       ),
       'uid' => array(
         'type' => 'int',
+        'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
         'description' => "User's {users}.uid.",
@@ -475,5 +476,13 @@ function user_update_8003() {
 }
 
 /**
+ * Make *id fields unsigned.
+ */
+function user_update_8004() {
+  $schema = drupal_get_schema('authmap', TRUE);
+  db_change_field('authmap', 'uid', 'uid', $schema['fields']['uid']);
+}
+
+/**
  * @} End of "addtogroup updates-7.x-to-8.x".
  */