diff --git a/Gemfile b/Gemfile
index caef6f5..9fa0565 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,4 +3,4 @@ source 'https://rubygems.org'
 gem 'rake'
 gem 'artii', '~>2.1.1'
 gem 'rasciiart', '~>0.0.9'
-gem 'redcarpet', '~>3.1.2'
+gem 'redcarpet', '~>3.5.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index 6bc135b..209e1ab 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,7 +7,7 @@ GEM
     rasciiart (0.0.9)
       rainbow (= 2.0.0)
       rmagick (= 2.15.4)
-    redcarpet (3.1.2)
+    redcarpet (3.5.1)
     rmagick (2.15.4)
 
 PLATFORMS
@@ -17,4 +17,4 @@ DEPENDENCIES
   artii (~> 2.1.1)
   rake
   rasciiart (~> 0.0.9)
-  redcarpet (~> 3.1.2)
+  redcarpet (~> 3.5.1)
diff --git a/vimdeck-without-ascii-art.gemspec b/vimdeck-without-ascii-art.gemspec
index a3dda7b..0244897 100644
--- a/vimdeck-without-ascii-art.gemspec
+++ b/vimdeck-without-ascii-art.gemspec
@@ -21,5 +21,5 @@ Gem::Specification.new do |s|
   s.bindir       = 'bin'
   s.executables  = ['vimdeck-without-ascii-art']
   s.add_runtime_dependency 'artii', '~>2.0.4'
-  s.add_runtime_dependency 'redcarpet', '~>3.1.2'
+  s.add_runtime_dependency 'redcarpet', '>=3.1.2', '<3.6.0'
 end
diff --git a/vimdeck.gemspec b/vimdeck.gemspec
index fe6c0b6..c67c80f 100644
--- a/vimdeck.gemspec
+++ b/vimdeck.gemspec
@@ -21,5 +21,5 @@ Gem::Specification.new do |s|
   s.executables  = ['vimdeck']
   s.add_runtime_dependency 'artii', '~>2.1.1'
   s.add_runtime_dependency 'rasciiart', '~>0.0.9'
-  s.add_runtime_dependency 'redcarpet', '~>3.1.2'
+  s.add_runtime_dependency 'redcarpet', '>=3.1.2', '<3.6.0'
 end