diff --git a/Gemfile.lock b/Gemfile.lock
index bc5b468b0..9bb383e39 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -101,7 +101,7 @@ GEM
       timers (>= 4.1.1)
     celluloid-supervision (0.20.6)
       timers (>= 4.1.1)
-    chunky_png (1.3.6)
+    chunky_png (1.3.8)
     cliver (0.3.2)
     coderay (1.1.1)
     coffee-rails (4.2.1)