diff --git a/src/Form/RevisionOverviewForm.php b/src/Form/RevisionOverviewForm.php
index 9743db5..fcb6d50 100755
--- a/src/Form/RevisionOverviewForm.php
+++ b/src/Form/RevisionOverviewForm.php
@@ -301,7 +301,8 @@ class RevisionOverviewForm extends FormBase {
     if ($revision_count > 1) {
       $build['submit'] = array(
         '#type' => 'submit',
-        '#value' => t('Compare'),
+        '#button_type' => 'primary',
+        '#value' => t('Compare selected revisions'),
         '#attributes' => array(
           'class' => array(
             'diff-button',
diff --git a/src/Tests/DiffAdminFormsTest.php b/src/Tests/DiffAdminFormsTest.php
index 0417f1b..96c590c 100644
--- a/src/Tests/DiffAdminFormsTest.php
+++ b/src/Tests/DiffAdminFormsTest.php
@@ -123,7 +123,7 @@ class DiffAdminFormsTest extends DiffTestBase {
     // Assert the diff display uses the classic layout.
     $node = $this->getNodeByTitle('greater_title');
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertLink('Unified fields');
     $this->assertLink('Split fields');
     $this->assertLink('Raw');
@@ -140,7 +140,7 @@ class DiffAdminFormsTest extends DiffTestBase {
 
     // Assert the diff display uses the markdown layout.
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertResponse(200);
     $this->assertNoLink('Unified fields');
     $this->assertLink('Split fields');
@@ -168,7 +168,7 @@ class DiffAdminFormsTest extends DiffTestBase {
 
     // Assert the diff display uses the single column layout.
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertResponse(200);
     $this->assertLink('Unified fields');
     $this->assertNoLink('Split fields');
diff --git a/src/Tests/DiffPluginEntityTest.php b/src/Tests/DiffPluginEntityTest.php
index 0fc9558..c9eb4ec 100644
--- a/src/Tests/DiffPluginEntityTest.php
+++ b/src/Tests/DiffPluginEntityTest.php
@@ -88,7 +88,7 @@ class DiffPluginEntityTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->assertText('Reference');
     $this->assertText('Article B');
     $this->assertText('Article C');
diff --git a/src/Tests/DiffPluginFileTest.php b/src/Tests/DiffPluginFileTest.php
index b8e2279..1f41f5b 100644
--- a/src/Tests/DiffPluginFileTest.php
+++ b/src/Tests/DiffPluginFileTest.php
@@ -109,7 +109,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
       'radios_left' => $revision1,
       'radios_right' => $revision3,
     ];
-    $this->drupalPostForm(NULL, $edit, t('Compare'));
+    $this->drupalPostForm(NULL, $edit, t('Compare selected revisions'));
     $this->assertText('File');
     $this->assertText('File: text-1.txt');
     $this->assertText('File ID: 4');
@@ -200,7 +200,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
       'radios_left' => $revision1,
       'radios_right' => $revision3,
     ];
-    $this->drupalPostForm(NULL, $edit, t('Compare'));
+    $this->drupalPostForm(NULL, $edit, t('Compare selected revisions'));
     $this->assertText('Image');
     $this->assertText('Image: image-test-transparent-indexed.gif');
     // Image title must be absent since it is not set in previous revisions.
@@ -218,7 +218,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
       'field_image[0][title]' => 'Image title updated',
     ];
     $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, t('Save and keep published'));
-    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare'));
+    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare selected revisions'));
     $rows = $this->xpath('//tbody/tr');
     // Image title and alternative text must be shown.
     $this->assertEqual(htmlspecialchars_decode(strip_tags($rows[2]->td[2]->asXML())), 'Alt: Image alt updated');
@@ -234,7 +234,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
     ];
     $this->drupalPostAjaxForm(NULL, $edit, 'node.field_image_plugin_settings_update');
     $this->drupalPostForm(NULL, [], t('Save'));
-    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare'));
+    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare selected revisions'));
     // Alt and title must be hidden.
     $this->assertText('File ID: 2');
 
@@ -246,7 +246,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
     ];
     $this->drupalPostAjaxForm(NULL, $edit, 'node.field_image_plugin_settings_update');
     $this->drupalPostForm(NULL, [], t('Save'));
-    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare'));
+    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare selected revisions'));
     // Alt and title must be hidden.
     $this->assertNoText('Alt: Image alt updated');
     $this->assertNoText('Alt: Image alt updated new');
@@ -261,7 +261,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
     ];
     $this->drupalPostAjaxForm(NULL, $edit, 'node.field_image_plugin_settings_update');
     $this->drupalPostForm(NULL, [], t('Save'));
-    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare'));
+    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare selected revisions'));
     $this->assertText('Alt: Image alt updated');
     $this->assertText('Alt: Image alt updated new');
     $this->assertNoText('Title: Image title updated');
@@ -277,7 +277,7 @@ class DiffPluginFileTest extends DiffPluginTestBase {
     ];
     $this->drupalPostAjaxForm(NULL, $edit, 'node.field_image_plugin_settings_update');
     $this->drupalPostForm(NULL, [], t('Save'));
-    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare'));
+    $this->drupalPostForm('node/' . $node->id() . '/revisions', [], t('Compare selected revisions'));
 
     // Assert the thumbnail is not displayed.
     $img1_url = file_create_url(\Drupal::token()->replace("public://styles/thumbnail/public/[date:custom:Y]-[date:custom:m]/" . $test_files['1']->name));
diff --git a/src/Tests/DiffPluginTest.php b/src/Tests/DiffPluginTest.php
index 3e29575..67c683b 100644
--- a/src/Tests/DiffPluginTest.php
+++ b/src/Tests/DiffPluginTest.php
@@ -85,7 +85,7 @@ class DiffPluginTest extends DiffPluginTestBase {
 
     // Check the difference between the last two revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
 
     // "changed" field is not displayed since there is no plugin for it. This
     // should not break the revisions comparison display.
@@ -116,7 +116,7 @@ class DiffPluginTest extends DiffPluginTestBase {
 
     // Check the "Text Field No Access" field is not displayed.
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertResponse(200);
     $this->assertNoText('field_diff_deny_access');
     $rows = $this->xpath('//tbody/tr');
@@ -155,7 +155,7 @@ class DiffPluginTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
 
     // Check diff for an applicable field of testTextPlugin.
     $this->assertText('Test Applicable');
@@ -202,7 +202,7 @@ class DiffPluginTest extends DiffPluginTestBase {
     $this->assertText('Changes on: Body');
 
     // Assert the revision comparison.
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertNoText('No visible changes.');
     $rows = $this->xpath('//tbody/tr');
     $diff_row = $rows[1]->td;
@@ -219,7 +219,7 @@ class DiffPluginTest extends DiffPluginTestBase {
     ];
     $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, t('Save and keep published'));
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertNoText('No visible changes.');
     // Assert that empty rows also show a line number.
     $rows = $this->xpath('//tbody/tr');
diff --git a/src/Tests/DiffPluginVariousTest.php b/src/Tests/DiffPluginVariousTest.php
index 7381c84..fdbe2bb 100644
--- a/src/Tests/DiffPluginVariousTest.php
+++ b/src/Tests/DiffPluginVariousTest.php
@@ -100,7 +100,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check the difference between the last two revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->assertText('Comments');
     $this->assertText('Comments for this entity are open.');
     $this->assertText('Comments for this entity are closed.');
@@ -152,7 +152,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check the difference between the last two revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->assertText('Email');
     $this->assertText('foo@example.com');
     $this->assertText('bar@example.com');
@@ -207,7 +207,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Compare the revisions.
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
 
     // Assert that the timestamp field does not show a unix time format.
     $this->assertText('Timestamp test');
@@ -278,7 +278,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertText('Link');
     $this->assertText('Google');
     $this->assertText('http://www.google.com');
@@ -339,7 +339,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertText('List');
     $this->assertText('value_a');
     $this->assertText('value_b');
@@ -373,7 +373,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertText('Text Field');
     $this->assertText('Text Long Field');
     $this->assertText('Foo');
@@ -415,7 +415,7 @@ class DiffPluginVariousTest extends DiffPluginTestBase {
 
     // Check differences between revisions.
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertText('Body');
     $this->assertText('Foo value');
     $this->assertText('Foo summary');
diff --git a/src/Tests/DiffRevisionTest.php b/src/Tests/DiffRevisionTest.php
index 102d910..4155402 100644
--- a/src/Tests/DiffRevisionTest.php
+++ b/src/Tests/DiffRevisionTest.php
@@ -81,7 +81,7 @@ class DiffRevisionTest extends DiffTestBase {
     $this->assertText('Initial revision.');
 
     // Compare the revisions in standard mode.
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->clickLink('Split fields');
     // Assert breadcrumbs are properly displayed.
     $this->assertRaw('<nav class="breadcrumb"');
@@ -235,7 +235,7 @@ class DiffRevisionTest extends DiffTestBase {
       'radios_left' => 3,
       'radios_right' => 4,
     ];
-    $this->drupalPostForm(NULL, $edit, t('Compare'));
+    $this->drupalPostForm(NULL, $edit, t('Compare selected revisions'));
     $this->clickLink('Strip tags');
     // Check markdown layout is used when navigating between revisions.
     $rows = $this->xpath('//tbody/tr');
@@ -354,7 +354,7 @@ class DiffRevisionTest extends DiffTestBase {
     $this->assertEqual(count($rows), 1);
 
     // Compare the revisions and assert the first error message.
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->assertText('Multiple revisions are needed for comparison.');
 
     // Create another revision, changing the node language back to English.
@@ -377,7 +377,7 @@ class DiffRevisionTest extends DiffTestBase {
     $this->assertNoFieldChecked('edit-node-revisions-table-1-select-column-two');
 
     // Compare the revisions and assert the second error message.
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     $this->assertText('Select two revisions to compare.');
 
     // Check the same revisions twice and compare.
@@ -385,7 +385,7 @@ class DiffRevisionTest extends DiffTestBase {
       'radios_left' => $revision3,
       'radios_right' => $revision3,
     ];
-    $this->drupalPostForm('/node/' . $node->id() . '/revisions', $edit, 'Compare');
+    $this->drupalPostForm('/node/' . $node->id() . '/revisions', $edit, 'Compare selected revisions');
     // Assert the third error message.
     $this->assertText('Select different revisions to compare.');
 
@@ -394,7 +394,7 @@ class DiffRevisionTest extends DiffTestBase {
       'radios_left' => $revision3,
       'radios_right' => $revision1,
     ];
-    $this->drupalPostForm('/node/' . $node->id() . '/revisions', $edit, 'Compare');
+    $this->drupalPostForm('/node/' . $node->id() . '/revisions', $edit, 'Compare selected revisions');
     $this->assertLinkByHref('node/' . $node->id() . '/revisions/view/' . $revision1 . '/' . $revision3);
   }
 
@@ -446,7 +446,7 @@ class DiffRevisionTest extends DiffTestBase {
     // Access revision of first node.
     $this->drupalGet('/node/' . $node_one->id());
     $this->clickLink(t('Revisions'));
-    $this->drupalPostForm(NULL, NULL, t('Compare'));
+    $this->drupalPostForm(NULL, NULL, t('Compare selected revisions'));
     // Revision section should appear.
     $this->assertResponse(200);
   }
diff --git a/src/Tests/DiffViewModeTest.php b/src/Tests/DiffViewModeTest.php
index 37f64aa..9ba0991 100644
--- a/src/Tests/DiffViewModeTest.php
+++ b/src/Tests/DiffViewModeTest.php
@@ -46,7 +46,7 @@ class DiffViewModeTest extends DiffTestBase {
 
     // Check the difference between the last two revisions.
     $this->drupalGet('node/' . $node->id() . '/revisions');
-    $this->drupalPostForm(NULL, [], t('Compare'));
+    $this->drupalPostForm(NULL, [], t('Compare selected revisions'));
     $this->assertNoText('Body');
     $this->assertNoText('Foo');
     $this->assertNoText('Fighters');