diff --git a/Lib/test/json_tests/test_fail.py b/Lib/test/json_tests/test_fail.py
index fcff1d4d410..7809056a731 100644
--- a/Lib/test/json_tests/test_fail.py
+++ b/Lib/test/json_tests/test_fail.py
@@ -1,13 +1,13 @@
 from test.json_tests import PyTest, CTest
 
-# Fri Dec 30 18:57:26 2005
+# 2007-10-05
 JSONDOCS = [
     # http://json.org/JSON_checker/test/fail1.json
     '"A JSON payload should be an object or array, not a string."',
     # http://json.org/JSON_checker/test/fail2.json
     '["Unclosed array"',
     # http://json.org/JSON_checker/test/fail3.json
-    '{unquoted_key: "keys must be quoted}',
+    '{unquoted_key: "keys must be quoted"}',
     # http://json.org/JSON_checker/test/fail4.json
     '["extra comma",]',
     # http://json.org/JSON_checker/test/fail5.json
@@ -33,7 +33,7 @@ JSONDOCS = [
     # http://json.org/JSON_checker/test/fail15.json
     '["Illegal backslash escape: \\x15"]',
     # http://json.org/JSON_checker/test/fail16.json
-    '["Illegal backslash escape: \\\'"]',
+    '[\\naked]',
     # http://json.org/JSON_checker/test/fail17.json
     '["Illegal backslash escape: \\017"]',
     # http://json.org/JSON_checker/test/fail18.json
@@ -50,6 +50,24 @@ JSONDOCS = [
     '["Bad value", truth]',
     # http://json.org/JSON_checker/test/fail24.json
     "['single quote']",
+    # http://json.org/JSON_checker/test/fail25.json
+    '["\ttab\tcharacter\tin\tstring\t"]',
+    # http://json.org/JSON_checker/test/fail26.json
+    '["tab\\   character\\   in\\  string\\  "]',
+    # http://json.org/JSON_checker/test/fail27.json
+    '["line\nbreak"]',
+    # http://json.org/JSON_checker/test/fail28.json
+    '["line\\\nbreak"]',
+    # http://json.org/JSON_checker/test/fail29.json
+    '[0e]',
+    # http://json.org/JSON_checker/test/fail30.json
+    '[0e+]',
+    # http://json.org/JSON_checker/test/fail31.json
+    '[0e+-1]',
+    # http://json.org/JSON_checker/test/fail32.json
+    '{"Comma instead if closing brace": true,',
+    # http://json.org/JSON_checker/test/fail33.json
+    '["mismatch"}',
     # http://code.google.com/p/simplejson/issues/detail?id=3
     '["A\u001FZ control characters in string"]',
 ]
diff --git a/Lib/test/json_tests/test_float.py b/Lib/test/json_tests/test_float.py
index a3441cf0435..38ef7e94b38 100644
--- a/Lib/test/json_tests/test_float.py
+++ b/Lib/test/json_tests/test_float.py
@@ -13,6 +13,21 @@ class TestFloat:
             self.assertEqual(self.dumps(num), str(num))
             self.assertEqual(int(self.dumps(num)), num)
 
+    def test_out_of_range(self):
+        self.assertEqual(self.loads('[23456789012E666]'), [float('inf')])
+        self.assertEqual(self.loads('[-23456789012E666]'), [float('-inf')])
+
+    def test_allow_nan(self):
+        for val in (float('inf'), float('-inf'), float('nan')):
+            out = self.dumps([val])
+            if val == val:  # inf
+                self.assertEqual(self.loads(out), [val])
+            else:  # nan
+                res = self.loads(out)
+                self.assertEqual(len(res), 1)
+                self.assertNotEqual(res[0], res[0])
+            self.assertRaises(ValueError, self.dumps, [val], allow_nan=False)
+
 
 class TestPyFloat(TestFloat, PyTest): pass
 class TestCFloat(TestFloat, CTest): pass
diff --git a/Lib/test/json_tests/test_pass1.py b/Lib/test/json_tests/test_pass1.py
index 036a2e414cb..52445f396e0 100644
--- a/Lib/test/json_tests/test_pass1.py
+++ b/Lib/test/json_tests/test_pass1.py
@@ -17,7 +17,7 @@ JSON = r'''
         "real": -9876.543210,
         "e": 0.123456789e-12,
         "E": 1.234567890E+34,
-        "":  23456789012E666,
+        "":  23456789012E66,
         "zero": 0,
         "one": 1,
         "space": " ",
@@ -28,6 +28,7 @@ JSON = r'''
         "alpha": "abcdefghijklmnopqrstuvwyz",
         "ALPHA": "ABCDEFGHIJKLMNOPQRSTUVWYZ",
         "digit": "0123456789",
+        "0123456789": "digit",
         "special": "`1~!@#$%^&*()_+-={':[,]}|;.</>?",
         "hex": "\u0123\u4567\u89AB\uCDEF\uabcd\uef4A",
         "true": true,
@@ -43,8 +44,7 @@ JSON = r'''
 
 ,
 
-4 , 5        ,          6           ,7        ],
-        "compact": [1,2,3,4,5,6,7],
+4 , 5        ,          6           ,7        ],"compact":[1,2,3,4,5,6,7],
         "jsontext": "{\"object with 1 member\":[\"array with 1 element\"]}",
         "quotes": "&#34; \u0022 %22 0x22 034 &#x22;",
         "\/\\\"\uCAFE\uBABE\uAB98\uFCDE\ubcda\uef4A\b\f\n\r\t`1~!@#$%^&*()_+-=[]{}|;:',./<>?"
@@ -55,9 +55,11 @@ JSON = r'''
 99.44
 ,
 
-1066
-
-
+1066,
+1e1,
+0.1e1,
+1e-1,
+1e00,2e+00,2e-00
 ,"rosebud"]
 '''
 
@@ -67,12 +69,6 @@ class TestPass1:
         res = self.loads(JSON)
         out = self.dumps(res)
         self.assertEqual(res, self.loads(out))
-        try:
-            self.dumps(res, allow_nan=False)
-        except ValueError:
-            pass
-        else:
-            self.fail("23456789012E666 should be out of range")
 
 
 class TestPyPass1(TestPass1, PyTest): pass
diff --git a/Misc/NEWS b/Misc/NEWS
index 5509349d157..eb3a98d4978 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -380,6 +380,9 @@ Extension Modules
 Tests
 -----
 
+- Issue #16559: Add more tests for the json module, including some from the
+  official test suite at json.org.  Patch by Serhiy Storchaka.
+
 - Issue #16115: Add some tests for the executable argument to
   subprocess.Popen().  Initial patch by Kushal Das.