diff --git a/olp-cpp-sdk-core/src/http/ios/OLPHttpTask.mm b/olp-cpp-sdk-core/src/http/ios/OLPHttpTask.mm
index bf26b8948..0bb9fa985 100644
--- a/olp-cpp-sdk-core/src/http/ios/OLPHttpTask.mm
+++ b/olp-cpp-sdk-core/src/http/ios/OLPHttpTask.mm
@@ -98,7 +98,9 @@ - (OLPHttpTaskStatus)restart {
   }
 
   if (_dataTask) {
-    _httpClient.toIgnoreResponse[_dataTask.taskDescription] = _dataTask;
+    @synchronized(_httpClient.toIgnoreResponse) {
+      _httpClient.toIgnoreResponse[_dataTask.taskDescription] = _dataTask;
+    }
     [_dataTask cancel];
     _dataTask = nil;
   }