diff --git a/sample_app/Gemfile b/sample_app/Gemfile
index a2f2ab7..f651954 100644
--- a/sample_app/Gemfile
+++ b/sample_app/Gemfile
@@ -8,7 +8,7 @@ gem "carrierwave", "~> 1.2", ">= 1.2.3"
 gem "faker", "1.9.1"
 gem "figaro", "~> 1.1", ">= 1.1.1"
 gem "kaminari"
-gem "mini_magick", "~> 4.8"
+gem "mini_magick", "~> 4.9"
 gem "sidekiq", "~> 5.0", ">= 5.0.5"
 
 gem "puma", "~> 3.11"
diff --git a/sample_app/Gemfile.lock b/sample_app/Gemfile.lock
index fc6bd39..95fd54e 100644
--- a/sample_app/Gemfile.lock
+++ b/sample_app/Gemfile.lock
@@ -316,7 +316,7 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     mimemagic (0.3.2)
-    mini_magick (4.8.0)
+    mini_magick (4.9.4)
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
     minitest (5.11.3)
@@ -463,7 +463,7 @@ DEPENDENCIES
   jquery-rails
   kaminari
   listen (>= 3.0.5, < 3.2)
-  mini_magick (~> 4.8)
+  mini_magick (~> 4.9)
   puma (~> 3.11)
   rails (~> 5.2.0)
   rubocop (~> 0.54.0)