diff --git a/src/Plugin/Block/InstagramBlockBlock.php b/src/Plugin/Block/InstagramBlockBlock.php
index b75e543..d21b3a7 100644
--- a/src/Plugin/Block/InstagramBlockBlock.php
+++ b/src/Plugin/Block/InstagramBlockBlock.php
@@ -76,6 +76,7 @@ class InstagramBlockBlock extends BlockBase implements ContainerFactoryPluginInt
    */
   public function defaultConfiguration() {
     return [
+      'user_id' => '',
       'count' => 4,
       'width' => 150,
       'height' => 150,
diff --git a/src/Tests/InstagramBlockPlaceBlockTest.php b/src/Tests/InstagramBlockPlaceBlockTest.php
index bc446ac..bb777e8 100644
--- a/src/Tests/InstagramBlockPlaceBlockTest.php
+++ b/src/Tests/InstagramBlockPlaceBlockTest.php
@@ -76,6 +76,7 @@ class InstagramBlockPlaceBlockTest extends WebTestBase {
     // Test context mapping with valid data.
     $this->drupalGet('admin/structure/block/manage/instagramblock');
     $edit = [
+      'settings[user_id]' => '412345678',
       'settings[count]' => '4',
       'settings[width]' => '150',
       'settings[height]' => '150',
@@ -85,26 +86,33 @@ class InstagramBlockPlaceBlockTest extends WebTestBase {
     $this->drupalPostForm(NULL, $edit, 'Save block');
     $this->assertText('The block configuration has been saved.', 'Block save without errors.');
 
+    // Test user_id with invalid data.
+    $edit = [
+      'settings[user_id]' => $this->randomString(9),
+    ];
+    $this->drupalPostForm('admin/structure/block/manage/instagramblock', $edit, 'Save block');
+    $this->assertText('User id must be a number.', 'Block failed to save.');
+
     // Test count with invalid data.
     $edit = [
       'settings[count]' => $this->randomString(4),
     ];
     $this->drupalPostForm('admin/structure/block/manage/instagramblock', $edit, 'Save block');
-    $this->assertText('Number of images to display. must be a number.', 'Block failed to save.');
+    $this->assertText('Number of images to display must be a number.', 'Block failed to save.');
 
     // Test width with invalid data.
     $edit = [
       'settings[width]' => $this->randomString(4),
     ];
     $this->drupalPostForm('admin/structure/block/manage/instagramblock', $edit, 'Save block');
-    $this->assertText('Image width in pixels. must be a number.', 'Block failed to save.');
+    $this->assertText('Image width in pixels must be a number.', 'Block failed to save.');
 
     // Test height with invalid data.
     $edit = [
       'settings[height]' => $this->randomString(4),
     ];
     $this->drupalPostForm('admin/structure/block/manage/instagramblock', $edit, 'Save block');
-    $this->assertText('Image height in pixels. must be a number.', 'Block failed to save.');
+    $this->assertText('Image height in pixels must be a number.', 'Block failed to save.');
 
     // Test cache_time_minutes with invalid data.
     $edit = [