diff --git a/Lib/json/__init__.py b/Lib/json/__init__.py
--- a/Lib/json/__init__.py
+++ b/Lib/json/__init__.py
@@ -310,6 +310,9 @@
     The ``encoding`` argument is ignored and deprecated.
 
     """
+    if not isinstance(s, str):
+        raise TypeError('the JSON object must be str, not {!r}'.format(
+                            s.__class__.__name__))
     if (cls is None and object_hook is None and
             parse_int is None and parse_float is None and
             parse_constant is None and object_pairs_hook is None and not kw):
diff --git a/Lib/test/test_json/test_decode.py b/Lib/test/test_json/test_decode.py
--- a/Lib/test/test_json/test_decode.py
+++ b/Lib/test/test_json/test_decode.py
@@ -70,5 +70,10 @@
         msg = 'escape'
         self.assertRaisesRegex(ValueError, msg, self.loads, s)
 
+    def test_invalid_input_type(self):
+        msg = 'the JSON object must be str'
+        for value in [1, 3.14, b'bytes', b'\xff\x00', [], {}, None]:
+            self.assertRaisesRegex(TypeError, msg, self.loads, value)
+
 class TestPyDecode(TestDecode, PyTest): pass
 class TestCDecode(TestDecode, CTest): pass