diff --git a/ChangeLog b/ChangeLog
index 21414ece3d..dfb242daaa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Mar  6 11:36:37 2005  Tanaka Akira  <akr@m17n.org>
+
+	* lib/pp.rb (File::Stat#pretty_print): Etc.getpwuid and Etc.getgrgid
+	  may return nil.  [ruby-talk:129826]
+	  reported by Daniel Berger.
+
 Sun Mar  6 06:34:31 2005  GOTOU Yuuzou  <gotoyuzo@notwork.org>
 
 	* ext/openssl/ossl_ssl.c (ossl_start_ssl): should wait for that
diff --git a/lib/pp.rb b/lib/pp.rb
index 756dce6f51..7cbbd8a0c0 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -407,19 +407,23 @@ class File
         q.group {
           q.text "uid="; q.pp self.uid
           begin
-            name = Etc.getpwuid(self.uid).name
-            q.breakable; q.text "(#{name})"
+            pw = Etc.getpwuid(self.uid)
           rescue ArgumentError
           end
+          if pw
+            q.breakable; q.text "(#{pw.name})"
+          end
         }
         q.comma_breakable
         q.group {
           q.text "gid="; q.pp self.gid
           begin
-            name = Etc.getgrgid(self.gid).name
-            q.breakable; q.text "(#{name})"
+            gr = Etc.getgrgid(self.gid)
           rescue ArgumentError
           end
+          if gr
+            q.breakable; q.text "(#{gr.name})"
+          end
         }
         q.comma_breakable
         q.group {