diff --git a/lib/u3d/commands.rb b/lib/u3d/commands.rb
index 7e97e111..5058e12a 100644
--- a/lib/u3d/commands.rb
+++ b/lib/u3d/commands.rb
@@ -275,10 +275,8 @@ def cache_versions(os, offline: false, force_refresh: false, central_cache: true
 
       def verify_package_names(packages, definition)
         unless packages.nil?
-          invalid_packages = packages.select { |package| !definition.available_package? package }
-          unless invalid_packages.empty?
-            raise ArgumentError, "Package(s) '#{invalid_packages.join(',')}' are not known. Use #{definition.available_packages.join(',')}"
-          end
+          invalid_packages = packages.reject { |package| definition.available_package? package }
+          raise ArgumentError, "Package(s) '#{invalid_packages.join(',')}' are not known. Use #{definition.available_packages.join(',')}" unless invalid_packages.empty?
         end
         packages
       end
@@ -437,4 +435,4 @@ def get_administrative_privileges(options)
 end
 
 class InstallationSetupError < StandardError
-end
\ No newline at end of file
+end
diff --git a/spec/u3d/commands_spec.rb b/spec/u3d/commands_spec.rb
index 2e24ebf7..76d15269 100644
--- a/spec/u3d/commands_spec.rb
+++ b/spec/u3d/commands_spec.rb
@@ -359,7 +359,7 @@
             ]
           )
 
-          expect{
+          expect do
             U3d::Commands.install(
               args: ['1.2.3f4'],
               options: {
@@ -368,7 +368,7 @@
                 packages: ['not.a.package']
               }
             )
-          }.to raise_error ArgumentError, /'not.a.package'/
+          end.to raise_error ArgumentError, /'not.a.package'/
         end
         #   support downloading the not current platform -> not yet supported
         #   TODO: Implement me