diff -r 9a3e60b74cc7 Lib/json/decoder.py
--- a/Lib/json/decoder.py	Fri Jan 31 16:07:32 2014 +0100
+++ b/Lib/json/decoder.py	Fri Jan 31 16:04:01 2014 +0000
@@ -188,7 +188,7 @@
         try:
             value, end = scan_once(s, end)
         except StopIteration as err:
-            raise ValueError(errmsg("Expecting value", s, err.value)) from None
+            raise ValueError(errmsg("No JSON object could be decoded, expecting value", s, err.value)) from None
         pairs_append((key, value))
         try:
             nextchar = s[end]
@@ -232,7 +232,7 @@
         try:
             value, end = scan_once(s, end)
         except StopIteration as err:
-            raise ValueError(errmsg("Expecting value", s, err.value)) from None
+            raise ValueError(errmsg("No JSON object could be decoded, expecting value", s, err.value)) from None
         _append(value)
         nextchar = s[end:end + 1]
         if nextchar in _ws:
@@ -358,5 +358,5 @@
         try:
             obj, end = self.scan_once(s, idx)
         except StopIteration as err:
-            raise ValueError(errmsg("Expecting value", s, err.value)) from None
+            raise ValueError(errmsg("No JSON object could be decoded, expecting value", s, err.value)) from None
         return obj, end
diff -r 9a3e60b74cc7 Lib/test/test_json/test_fail.py
--- a/Lib/test/test_json/test_fail.py	Fri Jan 31 16:07:32 2014 +0100
+++ b/Lib/test/test_json/test_fail.py	Fri Jan 31 16:04:01 2014 +0000
@@ -103,21 +103,24 @@
 
     def test_truncated_input(self):
         test_cases = [
-            ('', 'Expecting value', 0),
-            ('[', 'Expecting value', 1),
+            ('', 'No JSON object could be decoded, expecting value', 0),
+            ('[', 'No JSON object could be decoded, expecting value', 1),
             ('[42', "Expecting ',' delimiter", 3),
-            ('[42,', 'Expecting value', 4),
+            ('[42,', 'No JSON object could be decoded, expecting value', 4),
             ('["', 'Unterminated string starting at', 1),
             ('["spam', 'Unterminated string starting at', 1),
             ('["spam"', "Expecting ',' delimiter", 7),
-            ('["spam",', 'Expecting value', 8),
+            ('["spam",',
+             'No JSON object could be decoded, expecting value', 8),
             ('{', 'Expecting property name enclosed in double quotes', 1),
             ('{"', 'Unterminated string starting at', 1),
             ('{"spam', 'Unterminated string starting at', 1),
             ('{"spam"', "Expecting ':' delimiter", 7),
-            ('{"spam":', 'Expecting value', 8),
+            ('{"spam":',
+             'No JSON object could be decoded, expecting value', 8),
             ('{"spam":42', "Expecting ',' delimiter", 10),
-            ('{"spam":42,', 'Expecting property name enclosed in double quotes', 11),
+            ('{"spam":42,',
+             'Expecting property name enclosed in double quotes', 11),
         ]
         test_cases += [
             ('"', 'Unterminated string starting at', 0),
@@ -131,15 +134,17 @@
 
     def test_unexpected_data(self):
         test_cases = [
-            ('[,', 'Expecting value', 1),
-            ('{"spam":[}', 'Expecting value', 9),
+            ('[,', 'No JSON object could be decoded, expecting value', 1),
+            ('{"spam":[}',
+             'No JSON object could be decoded, expecting value', 9),
             ('[42:', "Expecting ',' delimiter", 3),
             ('[42 "spam"', "Expecting ',' delimiter", 4),
-            ('[42,]', 'Expecting value', 4),
+            ('[42,]', 'No JSON object could be decoded, expecting value', 4),
             ('{"spam":[42}', "Expecting ',' delimiter", 11),
             ('["]', 'Unterminated string starting at', 1),
             ('["spam":', "Expecting ',' delimiter", 7),
-            ('["spam",]', 'Expecting value', 8),
+            ('["spam",]',
+             'No JSON object could be decoded, expecting value', 8),
             ('{:', 'Expecting property name enclosed in double quotes', 1),
             ('{,', 'Expecting property name enclosed in double quotes', 1),
             ('{42', 'Expecting property name enclosed in double quotes', 1),
@@ -147,11 +152,14 @@
             ('{"spam",', "Expecting ':' delimiter", 7),
             ('{"spam"}', "Expecting ':' delimiter", 7),
             ('[{"spam"]', "Expecting ':' delimiter", 8),
-            ('{"spam":}', 'Expecting value', 8),
-            ('[{"spam":]', 'Expecting value', 9),
+            ('{"spam":}',
+             'No JSON object could be decoded, expecting value', 8),
+            ('[{"spam":]',
+             'No JSON object could be decoded, expecting value', 9),
             ('{"spam":42 "ham"', "Expecting ',' delimiter", 11),
             ('[{"spam":42]', "Expecting ',' delimiter", 11),
-            ('{"spam":42,}', 'Expecting property name enclosed in double quotes', 11),
+            ('{"spam":42,}',
+             'Expecting property name enclosed in double quotes', 11),
         ]
         for data, msg, idx in test_cases:
             self.assertRaisesRegex(ValueError,
@@ -186,7 +194,7 @@
         ]
         for data, line, col, idx in test_cases:
             self.assertRaisesRegex(ValueError,
-                r'^Expecting value: line {0} column {1}'
+                r'^No JSON object could be decoded, expecting value: line {0} column {1}'
                 r' \(char {2}\)$'.format(line, col, idx),
                 self.loads, data)