diff --git a/plugins/FeedsProcessor.inc b/plugins/FeedsProcessor.inc
index c2b0af5..7b97197 100755
--- a/plugins/FeedsProcessor.inc
+++ b/plugins/FeedsProcessor.inc
@@ -469,11 +469,13 @@ abstract class FeedsProcessor extends FeedsPlugin {
     // need to clear target elements of each item before mapping in case we are
     // mapping on a prepopulated item such as an existing node.
     foreach ($this->config['mappings'] as $mapping) {
-      if (isset($targets[$this->id][$mapping['target']]['real_target'])) {
-        unset($target_item->{$targets[$this->id][$mapping['target']]['real_target']});
-      }
-      elseif (isset($target_item->{$mapping['target']})) {
-        unset($target_item->{$mapping['target']});
+      if (empty($mapping['prevent_null_overwrite'])) {
+        if (isset($targets[$this->id][$mapping['target']]['real_target'])) {
+          $target_item->{$targets[$this->id][$mapping['target']]['real_target']} = NULL;
+        }
+        else {
+          $target_item->{$mapping['target']} = NULL;
+        }
       }
     }