diff --git a/Gemfile.lock b/Gemfile.lock
index 2d7eab2..9544a3a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,7 @@ PATH
     raddocs (2.3.0)
       haml (>= 4.0)
       json
-      sinatra
+      sinatra (>= 3.0)
 
 GEM
   remote: https://rubygems.org/
diff --git a/raddocs.gemspec b/raddocs.gemspec
index 49c371e..a4c31ce 100644
--- a/raddocs.gemspec
+++ b/raddocs.gemspec
@@ -14,7 +14,7 @@ Gem::Specification.new do |s|
 
   s.required_rubygems_version = ">= 1.3.6"
 
-  s.add_runtime_dependency "sinatra", "~> 2.0"
+  s.add_runtime_dependency "sinatra", ">= 3.0"
   s.add_runtime_dependency "haml", ">= 4.0"
   s.add_runtime_dependency "json"