diff --git a/modules/salesforce_mapping/src/SalesforceMappingFieldPluginBase.php b/modules/salesforce_mapping/src/SalesforceMappingFieldPluginBase.php
index 5f84b7f5ada3a00520476e730cb94395dd4bdff4..6a3dd71b1d25218246ee4e4cc54caa4e0d17b865 100644
--- a/modules/salesforce_mapping/src/SalesforceMappingFieldPluginBase.php
+++ b/modules/salesforce_mapping/src/SalesforceMappingFieldPluginBase.php
@@ -242,7 +242,7 @@ abstract class SalesforceMappingFieldPluginBase extends PluginBase implements Sa
         break;
     }
 
-    if ($field_definition['length'] > 0 && strlen($value) > $field_definition['length']) {
+    if (!empty($value) && $field_definition['length'] > 0 && strlen($value) > $field_definition['length']) {
       $value = substr($value, 0, $field_definition['length']);
     }