diff --git a/rdf-n3.gemspec b/rdf-n3.gemspec
index f7dac3b..21b65f8 100755
--- a/rdf-n3.gemspec
+++ b/rdf-n3.gemspec
@@ -22,18 +22,18 @@ Gem::Specification.new do |gem|
   gem.requirements          = []
 
   gem.add_dependency             'ebnf',            '~> 2.1'
-  gem.add_dependency             'rdf',             '~> 3.1'
-  gem.add_dependency             'sparql',          '~> 3.1'
+  gem.add_dependency             'rdf',             '~> 3.1', '>= 3.1.8'
+  gem.add_dependency             'sparql',          '~> 3.1', '>= 3.1.4'
   gem.add_runtime_dependency     'sxp',             '~> 1.1'
 
   gem.add_development_dependency 'json-ld',         '~> 3.1'
-  gem.add_development_dependency 'rspec',           '~> 3.9'
-  gem.add_development_dependency 'rspec-its',       '~> 1.3'
   gem.add_development_dependency 'rdf-spec',        '~> 3.1'
   gem.add_development_dependency 'rdf-isomorphic',  '~> 3.1'
   gem.add_development_dependency 'rdf-trig',        '~> 3.1'
   gem.add_development_dependency 'rdf-vocab',       '~> 3.1'
-  gem.add_development_dependency 'yard' ,           '~> 0.9.20'
+  gem.add_development_dependency 'rspec',           '~> 3.10'
+  gem.add_development_dependency 'rspec-its',       '~> 1.3'
+  gem.add_development_dependency 'yard' ,           '~> 0.9'
 
   gem.post_install_message  = nil
 end