diff --git a/mollom.module b/mollom.module
index 33cfc2e..24b0be4 100644
--- a/mollom.module
+++ b/mollom.module
@@ -551,7 +551,7 @@ function mollom_data_delete_form_alter(&$form, &$form_state) {
 function mollom_data_delete_form_submit($form, &$form_state) {
   $forms = mollom_form_cache();
   $mollom_form = mollom_form_load($forms['delete'][$form_state['values']['form_id']]);
-  $data = mollom_form_get_values($form_state['values'], $mollom_form['enabled_fields'], $mollom_form['mapping']);
+  $data = mollom_form_get_values($form_state, $mollom_form['enabled_fields'], $mollom_form['mapping']);
 
   $entity = $mollom_form['entity'];
   $id = $data['post_id'];
@@ -961,8 +961,11 @@ function mollom_form_delete($form_id) {
  *   specified data property. This is usually the case for form elements that
  *   hold system user information.
  *
- * @param $values
- *   An array containing submitted form values, usually $form_state['values'].
+ * @param $form_state
+ *   An associative array containing
+ *   - values: The submitted form values.
+ *   - buttons: A list of button form elements. See form_state_values_clean().
+ *   Not passed by reference.
  * @param $fields
  *   A list of strings representing form elements to extract. Nested fields are
  *   in the form of 'parent][child'.
@@ -972,9 +975,13 @@ function mollom_form_delete($form_id) {
  *
  * @see hook_mollom_form_info()
  */
-function mollom_form_get_values($form_values, $fields, $mapping) {
+function mollom_form_get_values($form_state, $fields, $mapping) {
   global $user;
 
+  // Remove all button values from $form_state['values'].
+  form_state_values_clean($form_state);
+  $form_values = $form_state['values'];
+
   // All elements specified in $mapping must be excluded from $fields, as they
   // are used for dedicated $data properties instead. To reduce the parsing code
   // size, we are turning a given $mapping of f.e.
@@ -1447,7 +1454,7 @@ function mollom_validate_analysis(&$form, &$form_state) {
   }
 
   // Perform textual analysis.
-  $all_data = mollom_form_get_values($form_state['values'], $form_state['mollom']['enabled_fields'], $form_state['mollom']['mapping']);
+  $all_data = mollom_form_get_values($form_state, $form_state['mollom']['enabled_fields'], $form_state['mollom']['mapping']);
   // Cancel processing upon invalid UTF-8 data.
   if ($all_data === FALSE) {
     return;
@@ -1598,7 +1605,7 @@ function mollom_validate_captcha(&$form, &$form_state) {
   // Next to the Mollom session id and captcha result, the Mollom back-end also
   // takes into account the author's IP and local user id (if registered). Any
   // other values are ignored.
-  $all_data = mollom_form_get_values($form_state['values'], $form_state['mollom']['enabled_fields'], $form_state['mollom']['mapping']);
+  $all_data = mollom_form_get_values($form_state, $form_state['mollom']['enabled_fields'], $form_state['mollom']['mapping']);
   // Cancel processing upon invalid UTF-8 data.
   if ($all_data === FALSE) {
     return;
@@ -1710,7 +1717,7 @@ function mollom_form_submit($form, &$form_state) {
     // new entity id value into $form_state['values'], so we need to rebuild the
     // data mapping. We do not care for the actual fields, only for the value of
     // the mapped post_id.
-    $values = mollom_form_get_values($form_state['values'], array(), $form_state['mollom']['mapping']);
+    $values = mollom_form_get_values($form_state, array(), $form_state['mollom']['mapping']);
     // We only consider non-empty and non-zero values as valid entity ids.
     if (!empty($values['post_id'])) {
       // Save the Mollom session data.
diff --git a/tests/mollom.test b/tests/mollom.test
index e04b5bf..d73c6d5 100644
--- a/tests/mollom.test
+++ b/tests/mollom.test
@@ -2663,7 +2663,8 @@ class MollomDataTestCase extends MollomWebTestCase {
       'name' => 'Drupaler',
       'mail' => 'drupaler@example.com',
     );
-    $data = mollom_form_get_values($values, $fields, $form_info['mapping']);
+    $form_state = array('values' => $values, 'buttons' => array());
+    $data = mollom_form_get_values($form_state, $fields, $form_info['mapping']);
 
     $this->assertSame('post_title', $data['post_title'], $values['subject']);
     $this->assertSame('post_body', $data['post_body'], $values['message'] . "\n" . $values['parent']['child']);
@@ -2680,7 +2681,8 @@ class MollomDataTestCase extends MollomWebTestCase {
       'message' => 'Bar',
       'name' => $this->admin_user->name,
     );
-    $data = mollom_form_get_values($values, $fields, $form_info['mapping']);
+    $form_state = array('values' => $values, 'buttons' => array());
+    $data = mollom_form_get_values($form_state, $fields, $form_info['mapping']);
 
     $this->assertSame('post_title', $data['post_title'], $values['subject']);
     $this->assertSame('post_body', $data['post_body'], $values['message']);
@@ -2694,6 +2696,25 @@ class MollomDataTestCase extends MollomWebTestCase {
   }
 
   /**
+   * Test that form button values are not contained in post_body sent to Mollom.
+   */
+  function testFormButtonValues() {
+    $this->drupalLogin($this->admin_user);
+    $this->setProtection('mollom_test_form');
+    $this->drupalLogout();
+
+    // Verify that neither the "Submit" nor the "Add" button value is contained
+    // in the post body.
+    $edit = array(
+      'title' => 'ham',
+      'body' => 'ham',
+    );
+    $this->drupalPost('mollom-test/form', $edit, 'Submit');
+    $data = $this->getServerRecord();
+    $this->assertFalse(preg_match('@Submit|Add@', $data['post_body']), 'Button values not found in post body.');
+  }
+
+  /**
    * Test submitted post and author information for textual analysis.
    */
   function testAnalysis() {