diff --git a/lib/thor/util.rb b/lib/thor/util.rb
index 8a2ccef1..6fa0b3d9 100644
--- a/lib/thor/util.rb
+++ b/lib/thor/util.rb
@@ -133,7 +133,7 @@ def find_class_and_command_by_namespace(namespace, fallback = true)
           *pieces, command  = namespace.split(":")
           namespace = pieces.join(":")
           namespace = "default" if namespace.empty?
-          klass = Thor::Base.subclasses.detect { |thor| thor.namespace == namespace && thor.commands.keys.include?(command) }
+          klass = Thor::Base.subclasses.detect { |thor| thor.namespace == namespace && thor.command_exists?(command) }
         end
         unless klass # look for a Thor::Group with the right name
           klass = Thor::Util.find_by_namespace(namespace)
diff --git a/spec/util_spec.rb b/spec/util_spec.rb
index 80665edc..54cc051b 100644
--- a/spec/util_spec.rb
+++ b/spec/util_spec.rb
@@ -114,6 +114,14 @@ def self.clear_user_home!
       expect(Thor::Util.find_class_and_command_by_namespace("fruits:apple")).to eq([Apple, "apple"])
       expect(Thor::Util.find_class_and_command_by_namespace("fruits:pear")).to eq([Pear, "pear"])
     end
+
+    it "returns correct Thor class and the command name with hypen when shared namespaces" do
+      expect(Thor::Util.find_class_and_command_by_namespace("fruits:rotten-apple")).to eq([Apple, "rotten-apple"])
+    end
+
+    it "returns correct Thor class and the associated alias command name when shared namespaces" do
+      expect(Thor::Util.find_class_and_command_by_namespace("fruits:ra")).to eq([Apple, "ra"])
+    end
   end
 
   describe "#thor_classes_in" do