diff --git a/service_win32.cpp b/service_win32.cpp
index b4e3c1f..93f8a8f 100644
--- a/service_win32.cpp
+++ b/service_win32.cpp
@@ -805,8 +805,10 @@ void TunsafeServiceServer::HandleDisconnect() {
 void TunsafeServiceServer::OnGraphAvailable() {
   if (want_graph_type_ != 0xffffffff) {
     LinearizedGraph *graph = service_backend_->backend_->GetGraph(want_graph_type_);
-    if (graph)
+    if (graph) {
       connection_->WritePacket(TS_SERVICE_MSG_GRAPH, (uint8*)graph, graph->total_size);
+      free(graph);
+    }
   }
 }
 
diff --git a/tunsafe_win32.cpp b/tunsafe_win32.cpp
index daea673..f786043 100644
--- a/tunsafe_win32.cpp
+++ b/tunsafe_win32.cpp
@@ -788,8 +788,9 @@ enum {
 };
 
 static void UpdateGraphReq() {
-  if (g_backend && (g_current_tab != 1 || !g_ui_visible))
-    g_backend->GetGraph(0);
+  if (g_backend && (g_current_tab != 1 || !g_ui_visible)) {
+    free(g_backend->GetGraph(-1));
+  }
 }
 
 static void UpdateTabSelection() {