diff --git a/IPython/core/magic.py b/IPython/core/magic.py
index 3b040a9..d2b8f47 100644
--- a/IPython/core/magic.py
+++ b/IPython/core/magic.py
@@ -953,6 +953,8 @@ Currently the magic system has the following functions:\n"""
                 except UnicodeEncodeError:
                     vstr = unicode(var).encode(DEFAULT_ENCODING,
                                                'backslashreplace')
+                except:
+                    vstr = "<object with id %d (repr failed)>" % id(var)
                 vstr = vstr.replace('\n','\\n')
                 if len(vstr) < 50:
                     print vstr
diff --git a/IPython/core/tests/test_magic.py b/IPython/core/tests/test_magic.py
index 257ae5d..530085a 100644
--- a/IPython/core/tests/test_magic.py
+++ b/IPython/core/tests/test_magic.py
@@ -376,6 +376,14 @@ def doctest_who():
     Out[7]: ['alpha', 'beta']
     """
 
+def test_whos():
+    """Check that whos is protected against objects where repr() fails."""
+    class A(object):
+        def __repr__(self):
+            raise Exception()
+    _ip.user_ns['a'] = A()
+    _ip.magic("whos")
+
 @py3compat.u_format
 def doctest_precision():
     """doctest for %precision