diff --git a/packages/xo-collection/src/index.js b/packages/xo-collection/src/index.js
index aac48e146..2842f9bbd 100644
--- a/packages/xo-collection/src/index.js
+++ b/packages/xo-collection/src/index.js
@@ -134,8 +134,8 @@ export default class Index {
     for (let key in items) {
       const prev = keysToHash[key]
       if (prev != null) {
-        delete keysToHash[key]
         delete itemsByHash[prev][key]
+        delete keysToHash[key]
       }
     }
   }
diff --git a/packages/xo-collection/src/unique-index.js b/packages/xo-collection/src/unique-index.js
index 321bcf4cc..eb70ef71c 100644
--- a/packages/xo-collection/src/unique-index.js
+++ b/packages/xo-collection/src/unique-index.js
@@ -115,8 +115,8 @@ export default class UniqueIndex {
     for (let key in items) {
       const prev = keysToHash[key]
       if (prev != null) {
-        delete keysToHash[key]
         delete itemByHash[prev]
+        delete keysToHash[key]
       }
     }
   }