diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index 191e2720..a9829048 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -666,15 +666,9 @@ int nghttp2_session_reprioritize_stream(
   assert(dep_stream);
 
   if (dep_stream == stream->dep_prev && !pri_spec->exclusive) {
-    /* This is minor optimization when just weight is changed.
-       Currently, we don't reschedule stream in this case, since we
-       don't retain enough information to do that
-       (descendant_last_cycle we used to schedule it).  This means new
-       weight is only applied in the next scheduling, and if weight is
-       drastically increased, library is not responding very quickly.
-       If this is really an issue, we will do workaround for this. */
-    dep_stream->sum_dep_weight += pri_spec->weight - stream->weight;
-    stream->weight = pri_spec->weight;
+    /* This is minor optimization when just weight is changed. */
+    nghttp2_stream_change_weight(stream, pri_spec->weight);
+
     return 0;
   }
 
diff --git a/lib/nghttp2_stream.c b/lib/nghttp2_stream.c
index 06b64850..e3280d43 100644
--- a/lib/nghttp2_stream.c
+++ b/lib/nghttp2_stream.c
@@ -222,6 +222,52 @@ void nghttp2_stream_reschedule(nghttp2_stream *stream) {
   }
 }
 
+void nghttp2_stream_change_weight(nghttp2_stream *stream, int32_t weight) {
+  nghttp2_stream *dep_stream;
+  uint64_t last_cycle;
+  uint64_t cycle;
+  int32_t old_weight;
+
+  if (stream->weight == weight) {
+    return;
+  }
+
+  old_weight = stream->weight;
+  stream->weight = weight;
+
+  dep_stream = stream->dep_prev;
+
+  if (!dep_stream) {
+    return;
+  }
+
+  dep_stream->sum_dep_weight += weight - old_weight;
+
+  if (!stream->queued) {
+    return;
+  }
+
+  last_cycle =
+      stream->cycle -
+      stream->last_writelen * NGHTTP2_MAX_WEIGHT / (uint32_t)old_weight;
+
+  cycle = stream_next_cycle(stream, last_cycle);
+
+  if (cycle < dep_stream->descendant_last_cycle) {
+    cycle = dep_stream->descendant_last_cycle;
+  }
+
+  nghttp2_pq_remove(&dep_stream->obq, &stream->pq_entry);
+
+  stream->cycle = cycle;
+  stream->seq = dep_stream->descendant_next_seq++;
+
+  nghttp2_pq_push(&dep_stream->obq, &stream->pq_entry);
+
+  DEBUGF(fprintf(stderr, "stream: stream=%d obq resched cycle=%ld\n",
+                 stream->stream_id, stream->cycle));
+}
+
 static nghttp2_stream *stream_last_sib(nghttp2_stream *stream) {
   for (; stream->sib_next; stream = stream->sib_next)
     ;
diff --git a/lib/nghttp2_stream.h b/lib/nghttp2_stream.h
index bbb8b9f3..123ea2f2 100644
--- a/lib/nghttp2_stream.h
+++ b/lib/nghttp2_stream.h
@@ -418,6 +418,12 @@ int nghttp2_stream_in_dep_tree(nghttp2_stream *stream);
  */
 void nghttp2_stream_reschedule(nghttp2_stream *stream);
 
+/*
+ * Changes |stream|'s weight to |weight|.  If |stream| is queued, it
+ * will be rescheduled based on new weight.
+ */
+void nghttp2_stream_change_weight(nghttp2_stream *stream, int32_t weight);
+
 /*
  * Returns a stream which has highest priority, updating
  * descendant_last_cycle of selected stream's ancestors.