diff --git a/core/modules/comment/comment.install b/core/modules/comment/comment.install
index 0a147b5d8e9..6692a954d4d 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.',
@@ -316,6 +319,54 @@ function comment_update_8001() {
   }
 }
 
+/**
+ * Make *id fields unsigned.
+ */
+function comment_update_8002() {
+  db_drop_index('comment', 'comment_num_new');
+  db_drop_index('comment', 'comment_nid_langcode');
+  db_change_field('comment', 'nid', 'nid',
+    array(
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+      'description' => 'The {node}.nid to which this comment is a reply.',
+    ),
+    array('indexes' => array(
+      'comment_num_new' => array('nid', 'status', 'created', 'cid', 'thread'),
+      'comment_nid_langcode' => array('nid', 'langcode'),
+    ))
+  );
+  db_drop_index('comment', 'comment_uid');
+  db_change_field('comment', 'uid', '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.',
+    ),
+    array('indexes' => array(
+      'comment_uid' => array('uid'),
+    ))
+  );
+
+  db_drop_index('node_comment_statistics', 'last_comment_uid');
+  db_change_field('node_comment_statistics', 'last_comment_uid', '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.',
+    ),
+    array('indexes' => array(
+      'last_comment_uid' => array('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 919bab3884e..398171ae562 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.',
@@ -106,6 +107,25 @@ function dblog_update_8000() {
   ));
 }
 
+/**
+ * Make *id fields unsigned.
+ */
+function dblog_update_8001() {
+  db_drop_index('watchdog', 'uid');
+  db_change_field('watchdog', 'uid', 'uid',
+    array(
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+      'description' => 'The {users}.uid of the user who triggered the event.',
+    ),
+    array('indexes' => array(
+      'uid' => array('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 eb9094b3653..ac777f3f442 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,
       ),
@@ -602,6 +606,63 @@ function node_update_8004() {
   }
 }
 
+/**
+ * Make *id fields unsigned.
+ */
+function node_update_8005() {
+  db_drop_index('node', 'uid');
+  db_change_field('node', 'uid', '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,
+    ),
+    array('indexes' => array(
+      'uid' => array('uid'),
+    ))
+  );
+
+  db_drop_index('node_revision', 'uid');
+  db_change_field('node_revision', 'uid', 'uid',
+    array(
+      'description' => 'The {users}.uid that created this version.',
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+    ),
+    array('indexes' => array(
+      'uid' => array('uid'),
+    ))
+  );
+
+  db_drop_primary_key('history');
+  db_drop_index('history', 'nid');
+  db_change_field('history', 'uid', 'uid',
+    array(
+      'description' => 'The {users}.uid that read the {node} nid.',
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+    )
+  );
+  db_change_field('history', 'nid', 'nid',
+    array(
+      'description' => 'The {node}.nid that was read.',
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+    ),
+    array('primary key' => array('uid', 'nid'), 'indexes' => array(
+      'nid' => array('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 97c55181800..c0d0a6fe80d 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 +137,20 @@ function statistics_update_8000() {
     'statistics_block_top_last_num' => 'block.popular.top_recent_limit',
   ));
 }
+
+/**
+ * Make *id fields unsigned.
+ */
+function statistics_update_8001() {
+  db_drop_primary_key('node_counter');
+  db_change_field('node_counter', 'nid', 'nid',
+    array(
+      'description' => 'The {node}.nid for these statistics.',
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+    ),
+    array('primary key' => array('nid'))
+  );
+}
diff --git a/core/modules/tracker/tracker.install b/core/modules/tracker/tracker.install
index 64dd8c42ee4..569f4889d47 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,
       ),
@@ -131,6 +132,26 @@ function tracker_update_8000() {
   ));
 }
 
+/**
+ * Make *id fields unsigned.
+ */
+function tracker_update_8001() {
+  db_drop_primary_key('tracker_user');
+  db_drop_index('tracker_user', 'tracker');
+  db_change_field('tracker_user', 'uid', 'uid',
+    array(
+      'description' => 'The {users}.uid of the node author or commenter.',
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+    ),
+    array('primary key' => array('nid', 'uid'), 'indexes' => array(
+      'tracker' => array('uid', 'published', 'changed'),
+    ))
+  );
+}
+
 /**
  * @} 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 9d7a4af637d..422dcfb247e 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.",
@@ -567,6 +568,21 @@ function user_update_8007() {
   ));
 }
 
+/**
+ * Make *id fields unsigned.
+ */
+function user_update_8008() {
+  db_change_field('authmap', 'uid', 'uid',
+    array(
+      'type' => 'int',
+      'unsigned' => TRUE,
+      'not null' => TRUE,
+      'default' => 0,
+      'description' => "User's {users}.uid.",
+    )
+  );
+}
+
 /**
  * @} End of "addtogroup updates-7.x-to-8.x".
  */