diff --git a/django/contrib/auth/management/commands/createsuperuser.py b/django/contrib/auth/management/commands/createsuperuser.py
index aaedcab0f4..32d845daef 100644
--- a/django/contrib/auth/management/commands/createsuperuser.py
+++ b/django/contrib/auth/management/commands/createsuperuser.py
@@ -57,10 +57,12 @@ class Command(BaseCommand):
         # Try to determine the current system user's username to use as a default.
         try:
             import pwd
-        except ImportError:
-            default_username = ''
-        else:
             default_username = pwd.getpwuid(os.getuid())[0].replace(' ', '').lower()
+        except (ImportError, KeyError):
+            # KeyError will be raised by getpwuid() if there is no
+            # corresponding entry in the /etc/passwd file (a very restricted
+            # chroot environment, for example).
+            default_username = ''
 
         # Determine whether the default username is taken, so we don't display
         # it as an option.