diff --git a/lib/um/topic.rb b/lib/um/topic.rb
index b85ae20..33a990b 100644
--- a/lib/um/topic.rb
+++ b/lib/um/topic.rb
@@ -26,7 +26,7 @@ class << self
     private
 
     def topic_file_path
-      tmp_dir_path = '/var/tmp/um/' + Etc.getlogin
+      tmp_dir_path = '/var/tmp/um/' + Etc.getpwuid.name
       FileUtils.mkdir_p tmp_dir_path
 
       tmp_dir_path + '/current.topic'
diff --git a/lib/um/umconfig.rb b/lib/um/umconfig.rb
index 728fa82..ac0fff0 100644
--- a/lib/um/umconfig.rb
+++ b/lib/um/umconfig.rb
@@ -110,7 +110,7 @@ class << self
     # Cache the current pages directory in a file. This is used by the bash
     # completion script to avoid spinning up Ruby.
     def write_pages_directory(pages_directory_path)
-      tmp_dir_path = '/var/tmp/um/' + Etc.getlogin
+      tmp_dir_path = '/var/tmp/um/' + Etc.getpwuid.name
       FileUtils.mkdir_p tmp_dir_path
 
       tmp_file_path = tmp_dir_path + '/current.pagedir'