diff --git a/Gemfile b/Gemfile
index 66d4dbb2..d2477435 100644
--- a/Gemfile
+++ b/Gemfile
@@ -72,7 +72,7 @@ gem 'faker', :group => [:development, :test]
 gem 'rspec-rails', :group => [:development, :test]
 gem 'capybara', :group => [:development, :test]
 # for file attachments
-gem 'paperclip', '~> 4.1'
+gem 'paperclip', '~> 5.2'
 # as interactive debugger in error pages
 gem 'web-console', '~> 2.0', group: :development
 # as deployer
diff --git a/Gemfile.lock b/Gemfile.lock
index 4129a295..58238283 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -61,8 +61,7 @@ GEM
       rack (>= 1.0.0)
       rack-test (>= 0.5.4)
       xpath (~> 2.0)
-    climate_control (0.0.3)
-      activesupport (>= 3.0)
+    climate_control (0.2.0)
     cliver (0.3.2)
     cocaine (0.5.8)
       climate_control (>= 0.0.3, < 1.0)
@@ -156,7 +155,7 @@ GEM
     method_source (0.8.2)
     middleware (0.1.0)
     mime-types (2.99.3)
-    mimemagic (0.3.0)
+    mimemagic (0.3.2)
     mina (0.3.8)
       open4 (~> 1.3.4)
       rake
@@ -170,12 +169,12 @@ GEM
       mini_portile2 (~> 2.1.0)
     open4 (1.3.4)
     orm_adapter (0.5.0)
-    paperclip (4.3.6)
-      activemodel (>= 3.2.0)
-      activesupport (>= 3.2.0)
+    paperclip (5.2.1)
+      activemodel (>= 4.2.0)
+      activesupport (>= 4.2.0)
       cocaine (~> 0.5.5)
       mime-types
-      mimemagic (= 0.3.0)
+      mimemagic (~> 0.3.0)
     parallel (1.12.0)
     parser (2.4.0.2)
       ast (~> 2.3)
@@ -354,7 +353,7 @@ DEPENDENCIES
   mina (~> 0.3)
   mousetrap-rails
   mysql2
-  paperclip (~> 4.1)
+  paperclip (~> 5.2)
   poltergeist
   pry-byebug
   pry-rails