diff --git a/jsonld.php b/jsonld.php
index 27f4938..a3320d3 100644
--- a/jsonld.php
+++ b/jsonld.php
@@ -1517,30 +1517,31 @@ class JsonLdProcessor {
 
         // preserve empty arrays
         if(count($expanded_value) === 0) {
-          $active_property = $this->_compactIri(
-            $active_ctx, $expanded_property, null, array('vocab' => true),
-            $element);
+          $item_active_property = $this->_compactIri(
+            $active_ctx, $expanded_property, $expanded_value,
+            array('vocab' => true), $element);
           self::addValue(
-            $rval, $active_property, array(), array('propertyIsArray' => true));
+            $rval, $item_active_property, array(),
+            array('propertyIsArray' => true));
         }
 
         // recusively process array values
         foreach($expanded_value as $expanded_item) {
           // compact property and get container type
-          $active_property = $this->_compactIri(
+          $item_active_property = $this->_compactIri(
             $active_ctx, $expanded_property, $expanded_item,
             array('vocab' => true), $element);
           $container = self::getContextValue(
-            $active_ctx, $active_property, '@container');
+            $active_ctx, $item_active_property, '@container');
 
           // remove any duplicates that were (presumably) generated by a
           // property generator
-          if(property_exists($active_ctx->mappings, $active_property)) {
-            $mapping = $active_ctx->mappings->{$active_property};
+          if(property_exists($active_ctx->mappings, $item_active_property)) {
+            $mapping = $active_ctx->mappings->{$item_active_property};
             if($mapping && $mapping->propertyGenerator) {
               $this->_findPropertyGeneratorDuplicates(
                 $active_ctx, $element, $expanded_property, $expanded_item,
-                $active_property, true);
+                $item_active_property, true);
             }
           }
 
@@ -1553,8 +1554,8 @@ class JsonLdProcessor {
 
           // recursively compact expanded item
           $compacted_item = $this->_compact(
-            $active_ctx, $active_property, $is_list ? $list : $expanded_item,
-            $options);
+            $active_ctx, $item_active_property,
+            $is_list ? $list : $expanded_item, $options);
 
           // handle @list
           if($is_list) {
@@ -1573,7 +1574,7 @@ class JsonLdProcessor {
               }
             }
             // can't use @list container for more than 1 list
-            else if(property_exists($rval, $active_property)) {
+            else if(property_exists($rval, $item_active_property)) {
               throw new JsonLdException(
                 'JSON-LD compact error; property has a "@list" @container ' .
                 'rule but there is more than a single @list that matches ' .
@@ -1586,11 +1587,11 @@ class JsonLdProcessor {
           // handle language and index maps
           if($container === '@language' || $container === '@index') {
             // get or create the map object
-            if(property_exists($rval, $active_property)) {
-              $map_object = $rval->{$active_property};
+            if(property_exists($rval, $item_active_property)) {
+              $map_object = $rval->{$item_active_property};
             }
             else {
-              $rval->{$active_property} = $map_object = new stdClass();
+              $rval->{$item_active_property} = $map_object = new stdClass();
             }
 
             // if container is a language map, simplify compacted value to
@@ -1614,7 +1615,7 @@ class JsonLdProcessor {
 
             // add compact value
             self::addValue(
-              $rval, $active_property, $compacted_item,
+              $rval, $item_active_property, $compacted_item,
               array('propertyIsArray' => $is_array));
           }
         }