diff --git a/compiler/optimizing/graph_visualizer.h b/compiler/optimizing/graph_visualizer.h
index f17ba3b..05984a0 100644
--- a/compiler/optimizing/graph_visualizer.h
+++ b/compiler/optimizing/graph_visualizer.h
@@ -61,7 +61,7 @@
    * If this visualizer is enabled, emit the compilation information
    * in `output_`.
    */
-  void DumpGraph(const char* pass_name);
+  void DumpGraph(const char* pass_name) const;
 
  private:
   std::ostream* const output_;