diff --git a/src/utils.py b/src/utils.py
index ae89259ce..3a5108a42 100755
--- a/src/utils.py
+++ b/src/utils.py
@@ -211,7 +211,10 @@ def perlReToPythonRe(s):
             flag |= getattr(re, c)
     except AttributeError:
         raise ValueError, 'Invalid flag: %s' % c
-    return re.compile(regexp, flag)
+    try:
+        return re.compile(regexp, flag)
+    except re.error, e:
+        raise ValueError, str(e)
 
 def perlReToReplacer(s):
     """Converts a string representation of a Perl regular expression (i.e.,
diff --git a/test/test_utils.py b/test/test_utils.py
index 7a9ac44ee..a3abbc289 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -118,6 +118,7 @@ class UtilsTest(unittest.TestCase):
         self.failUnless(r.search('/'))
         r = utils.perlReToPythonRe('m/cat/i')
         self.failUnless(r.search('CAT'))
+        self.assertRaises(ValueError, utils.perlReToPythonRe, 'm/?/')
 
     def testPerlReToReplacer(self):
         f = utils.perlReToReplacer('s/foo/bar/')