diff --git a/lib/cl/opt.rb b/lib/cl/opt.rb
index b79ddd6..46a03f5 100644
--- a/lib/cl/opt.rb
+++ b/lib/cl/opt.rb
@@ -37,7 +37,7 @@ def define(const)
     def name
       return @name if instance_variable_defined?(:@name)
       name = long.split(' ').first.match(OPT)[1] if long
-      @name = name.sub('-', '_').to_sym if name
+      @name = name.gsub('-', '_').to_sym if name
     end
 
     def type
diff --git a/spec/opts_spec.rb b/spec/opts_spec.rb
index 3bba6d4..aba909f 100644
--- a/spec/opts_spec.rb
+++ b/spec/opts_spec.rb
@@ -52,13 +52,16 @@
   end
 
   describe 'dashed opts' do
-    let(:opts) { ->(*) { opt('--one_two') } }
+    let(:opts) { ->(*) { opt('--one_two_three') } }
 
-    it { expect(cmd(%w(cmd --one_two)).opts[:one_two]).to be true }
-    it { expect(cmd(%w(cmd --one_two)).one_two?).to be true }
+    it { expect(cmd(%w(cmd --one_two_three)).opts[:one_two_three]).to be true }
+    it { expect(cmd(%w(cmd --one_two_three)).one_two_three?).to be true }
 
-    it { expect(cmd(%w(cmd --one-two)).opts[:one_two]).to be true }
-    it { expect(cmd(%w(cmd --one-two)).one_two?).to be true }
+    it { expect(cmd(%w(cmd --one-two-three)).opts[:one_two_three]).to be true }
+    it { expect(cmd(%w(cmd --one-two-three)).one_two_three?).to be true }
+
+    it { expect(cmd(%w(cmd --one-two_three)).opts[:one_two_three]).to be true }
+    it { expect(cmd(%w(cmd --one_two-three)).one_two_three?).to be true }
   end
 
   describe 'does not dasherize values' do