diff --git a/core/modules/block/src/Tests/BlockAdminThemeTest.php b/core/modules/block/src/Tests/BlockAdminThemeTest.php
index e2f44a3392d18cff9e77570e78f7461590dd7db0..7d34c3b14e65dace173447b243214064fa18abb9 100644
--- a/core/modules/block/src/Tests/BlockAdminThemeTest.php
+++ b/core/modules/block/src/Tests/BlockAdminThemeTest.php
@@ -21,7 +21,7 @@ class BlockAdminThemeTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = array('block');
+  public static $modules = array('block', 'contextual');
 
   /**
    * Check for the accessibility of the admin theme on the block admin page.
@@ -43,4 +43,40 @@ function testAdminTheme() {
     $this->drupalGet('admin/structure/block/list/bartik');
     $this->assertResponse(200);
   }
+
+  /**
+   * Ensure contextual links are disabled in Seven theme.
+   */
+  function testSevenAdminTheme() {
+    // Create administrative user.
+    $admin_user = $this->drupalCreateUser([
+      'access administration pages',
+      'administer themes',
+      'access contextual links',
+      'view the administration theme',
+    ]);
+    $this->drupalLogin($admin_user);
+
+    // Install admin theme and confirm that tab is accessible.
+    \Drupal::service('theme_handler')->install(['seven']);
+    $edit['admin_theme'] = 'seven';
+    $this->drupalPostForm('admin/appearance', $edit, t('Save configuration'));
+
+    // Define our block settings.
+    $settings = [
+      'theme' => 'seven',
+      'region' => 'header',
+    ];
+
+    // Place a block.
+    $block = $this->drupalPlaceBlock('local_tasks_block', $settings);
+
+    // Open admin page.
+    $this->drupalGet('admin');
+
+    // Check if contextual link classes are unavailable.
+    $this->assertNoRaw('<div data-contextual-id="block:block=' . $block->id() . ':langcode=en"></div>');
+    $this->assertNoRaw('contextual-region');
+  }
+
 }
diff --git a/core/themes/seven/seven.theme b/core/themes/seven/seven.theme
index 7bd56e04443fcc8f764db6f121faf30b5ad70f02..4f7946cb5e40a23abeb4854ebd45d2b07cccee4d 100644
--- a/core/themes/seven/seven.theme
+++ b/core/themes/seven/seven.theme
@@ -83,6 +83,20 @@ function seven_preprocess_block_content_add_list(&$variables) {
   }
 }
 
+/**
+ * Implements hook_preprocess_block() for block content.
+ *
+ * Disables contextual links for all blocks.
+ */
+function seven_preprocess_block(&$variables) {
+  if (isset($variables['title_suffix']['contextual_links'])) {
+    unset($variables['title_suffix']['contextual_links']);
+    unset($variables['elements']['#contextual_links']);
+
+    $variables['attributes']['class'] = array_diff($variables['attributes']['class'], ['contextual-region']);
+  }
+}
+
 /**
  * Implements hook_preprocess_HOOK() for block admin page templates.
  */