diff --git a/changelog.d/891.bugfix.rst b/changelog.d/891.bugfix.rst
new file mode 100644
index 000000000..a5ed17ae4
--- /dev/null
+++ b/changelog.d/891.bugfix.rst
@@ -0,0 +1,4 @@
+``parser.parse`` will now raise ``TypeError`` when ``tzinfos`` is passed a type
+that cannot be interpreted as a time zone. Prior to this change, it would raise
+an ``UnboundLocalError`` instead.
+Patch by @jbrockmendel (gh pr #891)
diff --git a/changelog.d/891.misc.rst b/changelog.d/891.misc.rst
new file mode 100644
index 000000000..2e7a44dd0
--- /dev/null
+++ b/changelog.d/891.misc.rst
@@ -0,0 +1,2 @@
+Added tests for tzinfos input types.
+Patch by @jbrockmendel (gh pr #891)
diff --git a/dateutil/parser/_parser.py b/dateutil/parser/_parser.py
index b70e2ca20..2ed091150 100644
--- a/dateutil/parser/_parser.py
+++ b/dateutil/parser/_parser.py
@@ -1172,6 +1172,9 @@ def _build_tzinfo(self, tzinfos, tzname, tzoffset):
             tzinfo = tz.tzstr(tzdata)
         elif isinstance(tzdata, integer_types):
             tzinfo = tz.tzoffset(tzname, tzdata)
+        else:
+            raise TypeError("Offset must be tzinfo subclass, tz string, "
+                            "or int offset.")
         return tzinfo
 
     def _build_tzaware(self, naive, res, tzinfos):
diff --git a/dateutil/test/test_parser.py b/dateutil/test/test_parser.py
index 7dc86751d..bf46dcecd 100644
--- a/dateutil/test/test_parser.py
+++ b/dateutil/test/test_parser.py
@@ -347,6 +347,62 @@ def test_parse_bytearray(self):
         assert res == expected
 
 
+class TestTzinfoInputTypes(object):
+    def assert_equal_same_tz(self, dt1, dt2):
+        assert dt1 == dt2
+        assert dt1.tzinfo is dt2.tzinfo
+
+    def test_tzinfo_dict_could_return_none(self):
+        dstr = "2017-02-03 12:40 BRST"
+        result = parse(dstr, tzinfos={"BRST": None})
+        expected = datetime(2017, 2, 3, 12, 40)
+        self.assert_equal_same_tz(result, expected)
+
+    def test_tzinfos_callable_could_return_none(self):
+        dstr = "2017-02-03 12:40 BRST"
+        result = parse(dstr, tzinfos=lambda *args: None)
+        expected = datetime(2017, 2, 3, 12, 40)
+        self.assert_equal_same_tz(result, expected)
+
+    def test_invalid_tzinfo_input(self):
+        dstr = "2014 January 19 09:00 UTC"
+        # Pass an absurd tzinfos object
+        tzinfos = {"UTC": ValueError}
+        with pytest.raises(TypeError):
+            parse(dstr, tzinfos=tzinfos)
+
+    def test_valid_tzinfo_tzinfo_input(self):
+        dstr = "2014 January 19 09:00 UTC"
+        tzinfos = {"UTC": tz.UTC}
+        expected = datetime(2014, 1, 19, 9, tzinfo=tz.UTC)
+        res = parse(dstr, tzinfos=tzinfos)
+        self.assert_equal_same_tz(res, expected)
+
+    def test_valid_tzinfo_unicode_input(self):
+        dstr = "2014 January 19 09:00 UTC"
+        tzinfos = {u"UTC": u"UTC+0"}
+        expected = datetime(2014, 1, 19, 9, tzinfo=tz.tzstr("UTC+0"))
+        res = parse(dstr, tzinfos=tzinfos)
+        self.assert_equal_same_tz(res, expected)
+
+    def test_valid_tzinfo_callable_input(self):
+        dstr = "2014 January 19 09:00 UTC"
+
+        def tzinfos(*args, **kwargs):
+            return u"UTC+0"
+
+        expected = datetime(2014, 1, 19, 9, tzinfo=tz.tzstr("UTC+0"))
+        res = parse(dstr, tzinfos=tzinfos)
+        self.assert_equal_same_tz(res, expected)
+
+    def test_valid_tzinfo_int_input(self):
+        dstr = "2014 January 19 09:00 UTC"
+        tzinfos = {u"UTC": -28800}
+        expected = datetime(2014, 1, 19, 9, tzinfo=tz.tzoffset(u"UTC", -28800))
+        res = parse(dstr, tzinfos=tzinfos)
+        self.assert_equal_same_tz(res, expected)
+
+
 class ParserTest(unittest.TestCase):
 
     @classmethod
@@ -507,14 +563,6 @@ def testUnspecifiedDayFallbackFebLeapYear(self):
         self.assertEqual(parse("Feb 2008", default=datetime(2010, 1, 31)),
                          datetime(2008, 2, 29))
 
-    def testTzinfoDictionaryCouldReturnNone(self):
-        self.assertEqual(parse('2017-02-03 12:40 BRST', tzinfos={"BRST": None}),
-                        datetime(2017, 2, 3, 12, 40))
-
-    def testTzinfosCallableCouldReturnNone(self):
-        self.assertEqual(parse('2017-02-03 12:40 BRST', tzinfos=lambda *args: None),
-                                    datetime(2017, 2, 3, 12, 40))
-
     def testErrorType01(self):
         with pytest.raises(ValueError):
             parse('shouldfail')