diff --git a/EntityDependencyIterator.inc b/EntityDependencyIterator.inc
index ad7bed3..2510f2b 100644
--- a/EntityDependencyIterator.inc
+++ b/EntityDependencyIterator.inc
@@ -126,9 +126,9 @@ class EntityDependencyIterator implements RecursiveIterator {
 
       // Don't add dependencies that already were checked.
       foreach ($this->dependencies as $entity_type => $dependencies) {
-        foreach ($dependencies as $entity_id) {
+        foreach ($dependencies as $key => $entity_id) {
           if (isset($this->checked[$entity_type][$entity_id])) {
-            unset($this->dependencies[$entity_type][$entity_id]);
+            unset($this->dependencies[$entity_type][$key]);
           }
           else {
             $this->causes[$entity_type][$entity_id] = array(