diff --git a/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php b/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
index 8723bbff8f452c5fda97679028482bc5736b0c8c..b25bdfb2300247839364b85a67d0511a685ab6e3 100644
--- a/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
+++ b/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
@@ -199,7 +199,7 @@ function testOptionsAllowedValuesText() {
   }
 
   /**
-   * Options (boolen) : test 'On/Off' values input.
+   * Options (boolean) : test 'On/Off' values input.
    */
   function testOptionsAllowedValuesBoolean() {
     $this->field_name = 'field_options_boolean';
@@ -225,6 +225,19 @@ function testOptionsAllowedValuesBoolean() {
     $this->assertFalse(isset($field['settings']['off']), 'The off value is not saved into settings');
   }
 
+  /**
+   * Options (text) : test 'trimmed values' input.
+   */
+  function testOptionsTrimmedValuesText() {
+    $this->field_name = 'field_options_trimmed_text';
+    $this->createOptionsField('list_text');
+
+    // Explicit keys.
+    $string = "zero |Zero\none | One";
+    $array = array('zero' => 'Zero', 'one' => 'One');
+    $this->assertAllowedValuesInput($string, $array, 'Explicit keys are accepted and trimmed.');
+  }
+
   /**
    * Helper function to create list field of a given type.
    *
diff --git a/core/modules/options/options.module b/core/modules/options/options.module
index b49d16b89393eba1ce0d8b871faedcf848c87b09..c63f3641914e819e151c09df78b789bb6cd87ef3 100644
--- a/core/modules/options/options.module
+++ b/core/modules/options/options.module
@@ -304,8 +304,9 @@ function options_extract_allowed_values($string, $field_type, $generate_keys) {
     // Check for an explicit key.
     $matches = array();
     if (preg_match('/(.*)\|(.*)/', $text, $matches)) {
-      $key = $matches[1];
-      $value = $matches[2];
+      // Trim key and value to avoid unwanted spaces issues.
+      $key = trim($matches[1]);
+      $value = trim($matches[2]);
       $explicit_keys = TRUE;
     }
     // Otherwise see if we can use the value as the key. Detecting true integer