diff --git a/net-smtp.gemspec b/net-smtp.gemspec
index c0a3a23..efc9b60 100644
--- a/net-smtp.gemspec
+++ b/net-smtp.gemspec
@@ -30,6 +30,4 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_dependency "net-protocol"
-  spec.add_dependency "digest"
-  spec.add_dependency "timeout"
 end