diff --git a/lib/thor/parser/option.rb b/lib/thor/parser/option.rb
index cb34d1ffd..4ced3fa8a 100644
--- a/lib/thor/parser/option.rb
+++ b/lib/thor/parser/option.rb
@@ -88,7 +88,7 @@ def usage(padding = 0)
       sample = "[#{sample}]" unless required?
 
       if boolean?
-        sample << ", [#{dasherize('no-' + human_name)}]" unless (name == "force") || name.start_with?("no-")
+        sample << ", [#{dasherize('no-' + human_name)}]" unless (name == "force") || name.start_with?("no-", "no_")
       end
 
       if aliases.empty?
diff --git a/spec/parser/option_spec.rb b/spec/parser/option_spec.rb
index 9e10972fb..e3b03c456 100644
--- a/spec/parser/option_spec.rb
+++ b/spec/parser/option_spec.rb
@@ -201,6 +201,7 @@ def option(name, options = {})
 
     it "does not document a negative option for a negative boolean" do
       expect(parse(:'no-foo', :boolean).usage).not_to include("[--no-no-foo]")
+      expect(parse(:no_foo, :boolean).usage).not_to include("[--no-no-foo]")
     end
 
     it "documents a negative option for a positive boolean starting with 'no'" do