diff --git a/constraints/constraint_history.inc b/constraints/constraint_history.inc
index 5748b0c..0130bb3 100644
--- a/constraints/constraint_history.inc
+++ b/constraints/constraint_history.inc
@@ -25,31 +25,21 @@ function password_policy_constraint_history_error($constraint) {
  * Password validation.
  */
 function password_policy_constraint_history_validate($password, $constraint, $uid) {
+  // Allow for backporting of phpass (Drupal 7 password caching). user_secure_hashing is implemented in password.inc.
+  if (function_exists('user_check_password')) {
+    $account = user_load($uid);
+    foreach (_password_policy_constraint_history_old_passwords($constraint, $uid) as $old_pass) {
+      $account->pass = $old_pass;
+      if (user_check_password($password, $account)) {
+        return FALSE;
+      }
+    }
+    return TRUE;
+  }
+  // user_check_password not found. Use md5 by default.
   return !in_array(md5($password), _password_policy_constraint_history_old_passwords($constraint, $uid));
 }
 
-/**
- * Javascript portion.
- */
-function password_policy_constraint_history_js($constraint, $uid) {
-  drupal_add_js(drupal_get_path('module', 'password_policy') .'/constraints/scripts/webtoolkit.md5.js');
-  $pass = _password_policy_constraint_history_old_passwords($constraint, $uid);
-  $s = '';
-  $s .= "  var num=0;\n";
-  $s .= "  var pass=new Array(\"". implode('","', $pass) ."\");\n";
-  $s .= "  var i;\n";
-  $s .= "  for (i=0;i<pass.length;i++) {\n";
-  $s .= "    if (pass[i] == MD5(value)) {\n";
-  $s .= "      num=1;\n";
-  $s .= "    }\n";
-  $s .= "  }\n";
-  $s .= "  if (num>0) {\n";
-  $s .= "    strength=\"low\";\n";
-  $s .= "    msg.push(translate.constraint_history);\n";
-  $s .= "  }\n";
-  return $s;
-}
-
 //////////////////////////////////////////////////////////////////////////////
 // Auxiliary
 
diff --git a/password_policy.install b/password_policy.install
index 5de577c..5acfd64 100644
--- a/password_policy.install
+++ b/password_policy.install
@@ -105,9 +105,9 @@ function password_policy_schema() {
           'not null' => TRUE,
         ),
         'pass' => array(
-          'description' => t("User's password (md5 hash)."),
+          'description' => t("User's password hash."),
           'type' => 'varchar',
-          'length' => 32,
+          'length' => 60,
           'not null' => TRUE,
         ),
         'created' => array(
@@ -356,3 +356,16 @@ function password_policy_update_6006() {
   array('rid','name'));
   return $ret;
 }
+
+/**
+* Alter table password_policy_history to accommodate phpass (D7 hashing method).
+*/
+function password_policy_update_6007() {
+  db_change_field($ret, 'password_policy_history', 'pass', 'pass', array(
+    'description' => t("User's password hash."),
+    'type' => 'varchar',
+    'length' => 60,
+    'not null' => TRUE,
+  ));
+  return $ret;
+}
\ No newline at end of file
diff --git a/password_policy.module b/password_policy.module
index 54942ff..c000ff3 100644
--- a/password_policy.module
+++ b/password_policy.module
@@ -237,7 +237,9 @@ function password_policy_user($op, &$edit, &$account, $category = NULL) {
         // New users do not yet have an uid during the validation step, but they do have at this insert step.
         // Store their first password in the system for use with the history constraint (if used).
         if ($account->uid) {
-          _password_policy_store_password($account->uid, $edit['pass']);
+          // Get the hashed password.
+          $account = user_load($account->uid);
+          _password_policy_store_hash($account->uid, $account->pass);
         }
       }
       break;
@@ -528,7 +530,9 @@ function password_policy_password_submit($form, &$form_state) {
 
   // Track the hashed password values which can then be used in the history constraint.
   if ($account->uid && !empty($values['pass'])) {
-    _password_policy_store_password($account->uid, $values['pass']);
+    // Get the hashed password.
+    $account = user_load($account->uid);
+    _password_policy_store_hash($account->uid, $account->pass);
   }
 }
 
@@ -796,8 +800,8 @@ function _password_policy_load_active_policy($roles) {
  * @param $pass
  *   Clear text password.
  */
-function _password_policy_store_password($uid, $pass) {
-  db_query("INSERT INTO {password_policy_history} (uid, pass, created) VALUES (%d, '%s', %d)", $uid, md5($pass), time());
+function _password_policy_store_hash($uid, $hash) {
+  db_query("INSERT INTO {password_policy_history} (uid, pass, created) VALUES (%d, '%s', %d)", $uid, $hash, time());
 }
 
 /**