diff --git a/fitparse/base.py b/fitparse/base.py
index b0ebf87..07d796d 100644
--- a/fitparse/base.py
+++ b/fitparse/base.py
@@ -76,12 +76,15 @@ def add_dev_field_description(self, message):
             self._append_dev_data_id(dev_data_index)
 
         fields = self.dev_types[int(dev_data_index)]['fields']
+        base_type = BASE_TYPES.get(base_type_id)
+        if base_type is None:
+            raise FitParseError("Unknown developer field base type: %s" % base_type_id)
 
         # Note that nothing in the spec says overwriting an existing field is invalid
         fields[field_def_num] = DevField(
             dev_data_index=dev_data_index,
             def_num=field_def_num,
-            type=BASE_TYPES[base_type_id],
+            type=base_type,
             name=field_name,
             units=units,
             native_field_num=native_field_num
diff --git a/tests/test.py b/tests/test.py
index e4851d5..c1440ef 100755
--- a/tests/test.py
+++ b/tests/test.py
@@ -74,6 +74,17 @@ def testfile(filename):
 
 
 class FitFileTestCase(unittest.TestCase):
+    def test_invalid_developer_base_type_raises_parse_error(self):
+        fit_data = generate_messages(
+            mesg_num=207, local_mesg_num=1, field_defs=[(3, 'uint8')], data=[[0]],
+        ) + generate_messages(
+            mesg_num=206, local_mesg_num=2,
+            field_defs=[(0, 'uint8'), (1, 'uint8'), (2, 'uint8')], data=[[0, 1, 255]],
+        )
+
+        with self.assertRaises(FitParseError):
+            FitFile(generate_fitfile(fit_data)).parse()
+
 
     def test_basic_file_with_one_record(self, endian='<'):
         f = FitFile(generate_fitfile(endian=endian))