diff --git a/test/rubygems/test_gem_ext_configure_builder.rb b/test/rubygems/test_gem_ext_configure_builder.rb
index 443d4b06b5..65d31f61af 100644
--- a/test/rubygems/test_gem_ext_configure_builder.rb
+++ b/test/rubygems/test_gem_ext_configure_builder.rb
@@ -46,13 +46,13 @@ class TestGemExtConfigureBuilder < Gem::TestCase
       end
     end
 
-    shell_error_msg = %r{(\./configure: .*)|(Can't open \./configure(?:: No such file or directory)?)}
+    shell_error_msg = %r{(\./configure: .*)|((?:Can't|cannot) open \./configure(?:: No such file or directory)?)}
     sh_prefix_configure = "sh ./configure --prefix="
 
     expected = %r(configure failed:
 
 #{Regexp.escape sh_prefix_configure}#{Regexp.escape @dest_path}
-.*?: #{shell_error_msg}
+(?:.*?: )?#{shell_error_msg}
 )
 
     assert_match expected, error.message