diff --git a/test/ruby/test_file_exhaustive.rb b/test/ruby/test_file_exhaustive.rb
index 2e563e53a8..b6090d009c 100644
--- a/test/ruby/test_file_exhaustive.rb
+++ b/test/ruby/test_file_exhaustive.rb
@@ -671,6 +671,7 @@ class TestFileExhaustive < Test::Unit::TestCase
 
   def test_expand_path_for_existent_username
     user = ENV['USER']
+    assert_not_empty(user)
     assert_equal(ENV['HOME'], File.expand_path("~#{user}"))
   end unless DRIVE