diff --git a/td/telegram/files/PartsManager.cpp b/td/telegram/files/PartsManager.cpp
index ed1d8ec32..1513e78ba 100644
--- a/td/telegram/files/PartsManager.cpp
+++ b/td/telegram/files/PartsManager.cpp
@@ -35,13 +35,14 @@ void PartsManager::set_streaming_offset(int64 offset) {
   };
   if (offset < 0 || need_check_ || (!unknown_size_flag_ && get_size() < offset)) {
     streaming_offset_ = 0;
+    LOG(ERROR) << "Ignore streaming_offset (1)";
     return;
   }
 
   auto part_i = offset / part_size_;
-  if (part_i >= MAX_PART_COUNT) {
+  if (use_part_count_limit_ && part_i >= MAX_PART_COUNT) {
     streaming_offset_ = 0;
-    // error?
+    LOG(ERROR) << "Ignore streaming_offset (2)";
     return;
   }
 
diff --git a/td/telegram/files/ResourceState.h b/td/telegram/files/ResourceState.h
index e0abf7285..47943e674 100644
--- a/td/telegram/files/ResourceState.h
+++ b/td/telegram/files/ResourceState.h
@@ -30,7 +30,10 @@ class ResourceState {
   }
 
   bool update_estimated_limit(int64 extra) {
-    auto new_estimated_limit = used_ + extra;
+    // unused() must be positive, i.e. used_ + using_ must be less than limit_
+    // TODO: use exact intersection between using_ and extra.
+    auto using_and_extra_intersection = min(using_, extra);  // between 0 and min(using_, extra)
+    auto new_estimated_limit = used_ + using_ + extra - using_and_extra_intersection;
 
     // Use extra extra limit
     if (new_estimated_limit < limit_) {