diff --git a/src/hb-coretext.cc b/src/hb-coretext.cc
index fbb165e96..15b8c62d7 100644
--- a/src/hb-coretext.cc
+++ b/src/hb-coretext.cc
@@ -598,7 +598,7 @@ _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
       } else {
         active_feature_t *feature = active_features.find (&event->feature);
 	if (feature)
-	  active_features.remove (feature - (active_feature_t *) active_features);
+	  active_features.remove (feature - active_features.arrayZ ());
       }
     }
   }
diff --git a/src/hb-uniscribe.cc b/src/hb-uniscribe.cc
index c403d1657..e98e41f9b 100644
--- a/src/hb-uniscribe.cc
+++ b/src/hb-uniscribe.cc
@@ -695,7 +695,7 @@ _hb_uniscribe_shape (hb_shape_plan_t    *shape_plan,
       {
         active_feature_t *feature = active_features.find (&event->feature);
 	if (feature)
-	  active_features.remove (feature - (active_feature_t *) active_features);
+	  active_features.remove (feature - active_features.arrayZ ());
       }
     }
 
@@ -886,8 +886,8 @@ retry:
 				     &items[i].a,
 				     script_tags[i],
 				     language_tag,
-				     range_char_counts,
-				     range_properties,
+				     range_char_counts.arrayZ (),
+				     range_properties.arrayZ (),
 				     range_properties.len,
 				     pchars + chars_offset,
 				     item_chars_len,
@@ -927,8 +927,8 @@ retry:
 				     &items[i].a,
 				     script_tags[i],
 				     language_tag,
-				     range_char_counts,
-				     range_properties,
+				     range_char_counts.arrayZ (),
+				     range_properties.arrayZ (),
 				     range_properties.len,
 				     pchars + chars_offset,
 				     log_clusters + chars_offset,