diff --git a/lib/Models/CustomField.php b/lib/Models/CustomField.php
index 91acc36c26..1279b5065f 100644
--- a/lib/Models/CustomField.php
+++ b/lib/Models/CustomField.php
@@ -148,4 +148,15 @@ class CustomField extends Model {
 
     return $custom_field->save();
   }
+
+  static function extractCustomFieldsFromFromObject($data) {
+    $custom_fields = array();
+    foreach($data as $key => $value) {
+      if(strpos($key, 'cf_') === 0) {
+        $custom_fields[(int)substr($key, 3)] = $value;
+        unset($data[$key]);
+      }
+    }
+    return array($data, $custom_fields);
+  }
 }
diff --git a/lib/Models/Subscriber.php b/lib/Models/Subscriber.php
index 0957ee650b..1ed1b058e2 100644
--- a/lib/Models/Subscriber.php
+++ b/lib/Models/Subscriber.php
@@ -491,27 +491,11 @@ class Subscriber extends Model {
       unset($data['segments']);
     }
 
-    if($subscriber === false) {
-      // fields that must exist
-      $not_null_fields = array(
-        'first_name' => '',
-        'last_name' => ''
-      );
-      foreach($not_null_fields as $field => $value) {
-        if(!isset($data[$field])) {
-          $data[$field] = $value;
-        }
-      }
-    }
+    // set required fields' default values
+    $data = self::setRequiredFieldsDefaultValues($data);
 
-    // custom fields
-    $custom_fields = array();
-    foreach($data as $key => $value) {
-      if(strpos($key, 'cf_') === 0) {
-        $custom_fields[(int)substr($key, 3)] = $value;
-        unset($data[$key]);
-      }
-    }
+    // get custom fields
+    list($data, $custom_fields) = CustomField::extractCustomFieldsFromFromObject($data);
 
     // wipe any unconfirmed data at this point
     $data['unconfirmed_data'] = null;
@@ -884,4 +868,17 @@ class Subscriber extends Model {
       }, $subscribers)
     );
   }
+
+  static function setRequiredFieldsDefaultValues($data) {
+    $required_field_default_values = array(
+      'first_name' => '',
+      'last_name' => ''
+    );
+    foreach($required_field_default_values as $field => $value) {
+      if(!isset($data[$field])) {
+        $data[$field] = $value;
+      }
+    }
+    return $data;
+  }
 }
\ No newline at end of file
diff --git a/tests/unit/Models/CustomFieldTest.php b/tests/unit/Models/CustomFieldTest.php
index 7e8387949f..432dfb3ac7 100644
--- a/tests/unit/Models/CustomFieldTest.php
+++ b/tests/unit/Models/CustomFieldTest.php
@@ -131,6 +131,30 @@ class CustomFieldTest extends MailPoetTest {
     expect($subscriber->value)->equals($association->value);
   }
 
+  function testItExtractsCustomFieldsFromObject() {
+    $data = array(
+      'email' => 'test@example.com',
+      'cf_1' => 'Paris',
+      'first_name' => 'John',
+      'cf_2' => 'France',
+      'last_name' => 'Doe'
+    );
+    list($data, $custom_values) = CustomField::extractCustomFieldsFromFromObject($data);
+    expect($data)->equals(
+      array(
+        'email' => 'test@example.com',
+        'first_name' => 'John',
+        'last_name' => 'Doe'
+      )
+    );
+    expect($custom_values)->equals(
+      array(
+        '1' => 'Paris',
+        '2' => 'France'
+      )
+    );
+  }
+
   function _after() {
     CustomField::deleteMany();
     Subscriber::deleteMany();
diff --git a/tests/unit/Models/SubscriberTest.php b/tests/unit/Models/SubscriberTest.php
index 719e02398a..ac4e6c6f42 100644
--- a/tests/unit/Models/SubscriberTest.php
+++ b/tests/unit/Models/SubscriberTest.php
@@ -903,6 +903,16 @@ class SubscriberTest extends MailPoetTest {
     );
   }
 
+  function testItSetsDefaultValuesForRequiredFields() {
+    // MySQL running in strict mode requires a value to be set for certain fields
+    expect(Subscriber::setRequiredFieldsDefaultValues(array()))->equals(
+      array(
+        'first_name' => '',
+        'last_name' => ''
+      )
+    );
+  }
+
   function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);