diff --git a/VERSION b/VERSION
index 15a2799..bea438e 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.3.0
+3.3.1
diff --git a/sinatra-rdf.gemspec b/sinatra-rdf.gemspec
index 104d95c..01be06a 100755
--- a/sinatra-rdf.gemspec
+++ b/sinatra-rdf.gemspec
@@ -29,7 +29,7 @@ Gem::Specification.new do |gem|
 
   gem.required_ruby_version      = '>= 3.0'
   gem.requirements               = []
-  gem.add_runtime_dependency     'rack-rdf',        '~> 3.3'
+  gem.add_runtime_dependency     'rack-rdf',        '~> 3.3', '>= 3.3.1'
   gem.add_runtime_dependency     'sinatra',         '~> 4.0'
 
   gem.add_development_dependency 'yard' ,           '~> 0.9'