diff --git a/core/lib/Drupal/Core/Config/Schema/Mapping.php b/core/lib/Drupal/Core/Config/Schema/Mapping.php
index 0caa9c7217ac43204cdbde9820a0a8e8a572a2df..19fb596647d23b11ad8fe08959cfec7df6fdc9da 100644
--- a/core/lib/Drupal/Core/Config/Schema/Mapping.php
+++ b/core/lib/Drupal/Core/Config/Schema/Mapping.php
@@ -103,16 +103,13 @@ public function toArray() {
    * @param string $name
    *   The name of property.
    *
-   * @return array|FALSE
-   *   The definition of the property or FALSE if the property does not exist.
+   * @return array|null
+   *   The definition of the property or NULL if the property does not exist.
    */
   public function getPropertyDefinition($name) {
     if (isset($this->definition['mapping'][$name])) {
       return $this->definition['mapping'][$name];
     }
-    else {
-      return FALSE;
-    }
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index b63a9d88f64bb80f062168982e10231d1f3c9d4a..992c7281a37db37a176386d0b8d21f89eb9094d6 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -478,9 +478,6 @@ public function getFieldDefinition($name) {
     if (isset($this->fieldDefinitions[$name])) {
       return $this->fieldDefinitions[$name];
     }
-    else {
-      return FALSE;
-    }
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityInterface.php b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
index 1314fd1d6449c9913ffd760427dfa320786f9075..654fc5eb77edac7690c959304a690c2a98a0d45b 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
@@ -109,8 +109,8 @@ public function hasField($field_name);
    * @param string $name
    *   The name of the field.
    *
-   * @return \Drupal\Core\Field\FieldDefinitionInterface|false
-   *   The definition of the field or FALSE if the field does not exist.
+   * @return \Drupal\Core\Field\FieldDefinitionInterface|null
+   *   The definition of the field or null if the field does not exist.
    */
   public function getFieldDefinition($name);