diff --git a/pyxform/survey_element.py b/pyxform/survey_element.py
index c09293732..6a07bfaca 100644
--- a/pyxform/survey_element.py
+++ b/pyxform/survey_element.py
@@ -1,10 +1,13 @@
+import re
+
 import json
 
 from pyxform import constants
-from pyxform.utils import is_valid_xml_tag, node, unicode
-from pyxform.xls2json import print_pyobj_to_json
-from pyxform.question_type_dictionary import QUESTION_TYPE_DICT
 from pyxform.errors import PyXFormError
+from pyxform.question_type_dictionary import QUESTION_TYPE_DICT
+from pyxform.utils import is_valid_xml_tag, node, unicode, \
+    INVALID_XFORM_TAG_REGEXP
+from pyxform.xls2json import print_pyobj_to_json
 
 try:
     from functools import lru_cache
@@ -136,9 +139,12 @@ def add_children(self, children):
 
     def validate(self):
         if not is_valid_xml_tag(self.name):
-            msg = "The name '%s' is an invalid xml tag. Names must begin with" \
-                  " a letter, colon, or underscore, subsequent characters can" \
-                  " include numbers, dashes, and periods." % self.name
+            invalid_char = re.search(INVALID_XFORM_TAG_REGEXP, self.name)
+            msg = "The name '{}' is an invalid XML tag, it contains an " \
+                  "invalid character '{}'. Names must begin with a letter, " \
+                  "colon, or underscore, subsequent characters can include " \
+                  "numbers, dashes, and periods".format(
+                self.name, invalid_char.group(0))
             raise PyXFormError(msg)
 
     # TODO: Make sure renaming this doesn't cause any problems
diff --git a/pyxform/tests_v1/test_sheet_columns.py b/pyxform/tests_v1/test_sheet_columns.py
index f3b94928e..49f5ab1c5 100644
--- a/pyxform/tests_v1/test_sheet_columns.py
+++ b/pyxform/tests_v1/test_sheet_columns.py
@@ -129,6 +129,25 @@ def test_missing_list_name(self):
                 'list name',
             ])
 
+    def test_clear_filename_error_message(self):
+        """Test clear filename error message"""
+        error_message = "The name 'bad@filename' is an invalid XML tag, it " \
+                        "contains an invalid character '@'. Names must begin" \
+                        " with a letter, colon, or underscore, subsequent " \
+                        "characters can include numbers, dashes, and periods"
+        self.assertPyxformXform(
+            name='bad@filename',
+            ss_structure=self._simple_choice_ss([
+                {'list_name': 'l1',
+                    'name': 'c1',
+                    'label': 'choice 1'},
+                {'list_name': 'l1',
+                    'name': 'c2',
+                    'label': 'choice 2'}]),
+            errored=True,
+            error__contains=[error_message]
+            )
+
 
 class AliasesTests(PyxformTestCase):
     """
diff --git a/pyxform/utils.py b/pyxform/utils.py
index 524d32136..d031974c8 100644
--- a/pyxform/utils.py
+++ b/pyxform/utils.py
@@ -32,6 +32,9 @@
     "start": TAG_START_CHAR,
     "char": TAG_CHAR
 }
+
+INVALID_XFORM_TAG_REGEXP = r"[^a-zA-Z:_][^a-zA-Z:_0-9\-.]*"
+
 NSMAP = {
     u"xmlns": u"http://www.w3.org/2002/xforms",
     u"xmlns:h": u"http://www.w3.org/1999/xhtml",