diff --git a/Lib/test/test_grp.py b/Lib/test/test_grp.py
index f7d2191..2c3ab29 100755
--- a/Lib/test/test_grp.py
+++ b/Lib/test/test_grp.py
@@ -42,6 +42,8 @@
         bynames = {}
         bygids = {}
         for (n, p, g, mem) in grp.getgrall():
+            if not n or n == '+':
+                continue # skip NIS entries etc.
             bynames[n] = g
             bygids[g] = n
 
diff --git a/Lib/test/test_pwd.py b/Lib/test/test_pwd.py
index 69d88dd..12d2bc9 100644
--- a/Lib/test/test_pwd.py
+++ b/Lib/test/test_pwd.py
@@ -38,8 +38,8 @@
         # check whether the entry returned by getpwuid()
         # for each uid is among those from getpwall() for this uid
         for e in entries:
-            if e[0] == '+':
-                continue # skip NIS entries
+            if not e[0] or e[0] == '+':
+                continue # skip NIS entries etc.
             self.assert_(pwd.getpwnam(e.pw_name) in entriesbyname[e.pw_name])
             self.assert_(pwd.getpwuid(e.pw_uid) in entriesbyuid[e.pw_uid])