diff --git a/lib/liquid/profiler.rb b/lib/liquid/profiler.rb
index dc9db60..51286c2 100644
--- a/lib/liquid/profiler.rb
+++ b/lib/liquid/profiler.rb
@@ -66,7 +66,7 @@ module Liquid
       end
 
       def render_time
-        @end_time - @start_time
+        @render_time = @end_time - @start_time
       end
     end