diff --git a/core/modules/migrate/src/Entity/Migration.php b/core/modules/migrate/src/Entity/Migration.php
index f07ba40..78a0605 100644
--- a/core/modules/migrate/src/Entity/Migration.php
+++ b/core/modules/migrate/src/Entity/Migration.php
@@ -407,13 +407,23 @@ public function setProcess(array $process) {
   /**
    * {@inheritdoc}
    */
-  public function setProcessOfProperty($field_name, $process, $merge = TRUE) {
-    if (isset($this->process[$field_name]) && is_array($process) && $merge) {
+  public function setProcessOfProperty($field_name, $process) {
+    $this->process[$field_name] = $process;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function mergeProcessOfProperty($field_name, array $process) {
+    // If we already have a process value then merge the incoming process array
+    //otherwise simply set it.
+    if (isset($this->process[$field_name])) {
       $this->process = NestedArray::mergeDeepArray([$this->process, [$field_name => $process]], TRUE);
     }
     else {
-      $this->process[$field_name] = $process;
+      $this->setProcessOfProperty($field_name, $process);
     }
+
     return $this;
   }
 
diff --git a/core/modules/migrate/src/Entity/MigrationInterface.php b/core/modules/migrate/src/Entity/MigrationInterface.php
index ca9ac03..fc575a2 100644
--- a/core/modules/migrate/src/Entity/MigrationInterface.php
+++ b/core/modules/migrate/src/Entity/MigrationInterface.php
@@ -202,17 +202,30 @@ public function setProcess(array $process);
    *
    * @param string $field_name
    *   The field name of which to set the process.
+   * @param mixed $process
+   *   A valid process value, array or string.
+   *
+   * @return $this
+   *   The migration entity.
+   *
+   * @see Drupal\migrate_drupal\Plugin\migrate\load\LoadEntity::processLinkField().
+   */
+  public function setProcessOfProperty($field_name, $process);
+
+  /**
+   * Merge the process arrays for an individual field.
+   *
+   * @param string $field_name
+   *   The field name of which to set the process.
    * @param array $process
    *   An array of process data.
-   * @param boolean $merge
-   *   (optional) TRUE if we should merge the process arrays otherwise FALSE.
    *
    * @return $this
    *   The migration entity.
    *
    * @see Drupal\migrate_drupal\Plugin\migrate\load\LoadEntity::processLinkField().
    */
-  public function setProcessOfProperty($field_name, $process, $merge = TRUE);
+  public function mergeProcessOfProperty($field_name, array $process);
 
   /**
    * Get the current system of record of the migration.
diff --git a/core/modules/migrate_drupal/src/Plugin/migrate/load/LoadEntity.php b/core/modules/migrate_drupal/src/Plugin/migrate/load/LoadEntity.php
index 7de8883..f04672d 100644
--- a/core/modules/migrate_drupal/src/Plugin/migrate/load/LoadEntity.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/load/LoadEntity.php
@@ -150,7 +150,7 @@ protected function processTextField($field_name, $field_data, MigrationInterface
         'source' => $format_key,
       ],
     ];
-    $migration->setProcessOfProperty("$field_name/format", $process);
+    $migration->mergeProcessOfProperty("$field_name/format", $process);
   }
 
   /**
@@ -172,7 +172,7 @@ protected function processFileField($field_name, $field_data, MigrationInterface
         $field_name . '_data',
       ],
     ];
-    $migration->setProcessOfProperty($field_name, $process);
+    $migration->mergeProcessOfProperty($field_name, $process);
   }
 
   /**
@@ -196,7 +196,7 @@ protected function processLinkField($field_name, $field_data, MigrationInterface
         $field_name . '_attributes',
       ],
     ];
-    $migration->setProcessOfProperty($field_name, $process);
+    $migration->mergeProcessOfProperty($field_name, $process);
   }
 
 }