diff --git a/plugins/FeedsProcessor.inc b/plugins/FeedsProcessor.inc
index d2d13dd..79c5d38 100644
--- a/plugins/FeedsProcessor.inc
+++ b/plugins/FeedsProcessor.inc
@@ -715,24 +715,26 @@ abstract class FeedsProcessor extends FeedsPlugin {
     // Many mappers add to existing fields rather than replacing them. Hence we
     // 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->getMappings() as $mapping) {
-      if (isset($targets[$mapping['target']]['real_target'])) {
-        $target_name = $targets[$mapping['target']]['real_target'];
-      }
-      else {
-        $target_name = $mapping['target'];
-      }
-
-      // If the target is a field empty the value for the targeted language
-      // only.
-      // In all other cases, just empty the target completely.
-      if (isset($fields[$target_name])) {
-        // Empty the target for the specified language.
-        $target_item->{$target_name}[$mapping['language']] = array();
-      }
-      else {
-        // Empty the whole target.
-        $target_item->{$target_name} = NULL;
+    // First, allow processors to disable "nulling" of values when empty.
+    if (empty($this->config['prevent_null_overwrite'])) {
+      foreach ($this->getMappings() as $mapping) {
+        if (isset($targets[$mapping['target']]['real_target'])) {
+          $target_name = $targets[$mapping['target']]['real_target'];
+        }
+        else {
+          $target_name = $mapping['target'];
+        }
+        // If the target is a field empty the value for the targeted language
+        // only.
+        // In all other cases, just empty the target completely.
+        if (isset($fields[$target_name])) {
+          // Empty the target for the specified language.
+          $target_item->{$target_name}[$mapping['language']] = array();
+        }
+        else {
+          // Empty the whole target.
+          $target_item->{$target_name} = NULL;
+        }
       }
     }