diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 4057ba1..9fa973e 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -853,6 +853,12 @@
         self.assertRaises(ValueError, int, "0x", 16)
         self.assertRaises(ValueError, int, "0x", 0)
 
+        self.assertRaises(ValueError, int, "0o", 8)
+        self.assertRaises(ValueError, int, "0o", 0)
+
+        self.assertRaises(ValueError, int, "0b", 2)
+        self.assertRaises(ValueError, int, "0b", 0)
+
 
         # SF bug 1334662: int(string, base) wrong answers
         # Various representations of 2**32 evaluated to 0
@@ -894,6 +900,45 @@
         self.assertEqual(int('2br45qb', 35), 4294967296L)
         self.assertEqual(int('1z141z4', 36), 4294967296L)
 
+        # tests with base 0
+        # this fails on 3.0, but in 2.x the old octal syntax is allowed
+        self.assertEqual(int(' 0123  ', 0), 83)
+        self.assertEqual(int(' 0123  ', 0), 83)
+        self.assertEqual(int('000', 0), 0)
+        self.assertEqual(int('0o123', 0), 83)
+        self.assertEqual(int('0x123', 0), 291)
+        self.assertEqual(int('0b100', 0), 4)
+        self.assertEqual(int(' 0O123   ', 0), 83)
+        self.assertEqual(int(' 0X123  ', 0), 291)
+        self.assertEqual(int(' 0B100 ', 0), 4)
+
+        # without base still base 10
+        self.assertEqual(int('0123'), 123)
+        self.assertEqual(int('0123', 10), 123)
+
+        # tests with prefix and base != 0
+        self.assertEqual(int('0x123', 16), 291)
+        self.assertEqual(int('0o123', 8), 83)
+        self.assertEqual(int('0b100', 2), 4)
+        self.assertEqual(int('0X123', 16), 291)
+        self.assertEqual(int('0O123', 8), 83)
+        self.assertEqual(int('0B100', 2), 4)
+
+        # the code has special checks for the first character after the
+        #  type prefix
+        self.assertRaises(ValueError, int, '0b2', 2)
+        self.assertRaises(ValueError, int, '0b02', 2)
+        self.assertRaises(ValueError, int, '0B2', 2)
+        self.assertRaises(ValueError, int, '0B02', 2)
+        self.assertRaises(ValueError, int, '0o8', 8)
+        self.assertRaises(ValueError, int, '0o08', 8)
+        self.assertRaises(ValueError, int, '0O8', 8)
+        self.assertRaises(ValueError, int, '0O08', 8)
+        self.assertRaises(ValueError, int, '0xg', 16)
+        self.assertRaises(ValueError, int, '0x0g', 16)
+        self.assertRaises(ValueError, int, '0Xg', 16)
+        self.assertRaises(ValueError, int, '0X0g', 16)
+
         # SF bug 1334662: int(string, base) wrong answers
         # Checks for proper evaluation of 2**32 + 1
         self.assertEqual(int('100000000000000000000000000000001', 2), 4294967297L)
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index 367a694..465a90c 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -180,7 +180,9 @@
 
     def test_literals_with_leading_zeroes(self):
         for arg in ["077787", "0xj", "0x.", "0e",  "090000000000000",
-                    "080000000000000", "000000000000009", "000000000000008"]:
+                    "080000000000000", "000000000000009", "000000000000008",
+                    "0b42", "0BADCAFE", "0o123456789", "0b1.1", "0o4.2",
+                    "0b101j2", "0o153j2", "0b100e1", "0o777e1"]:
             self.assertRaises(SyntaxError, eval, arg)
 
         self.assertEqual(eval("0777"), 511)
@@ -208,6 +210,10 @@
         self.assertEqual(eval("000000000000007"), 7)
         self.assertEqual(eval("000000000000008."), 8.)
         self.assertEqual(eval("000000000000009."), 9.)
+        self.assertEqual(eval("0b101010"), 42)
+        self.assertEqual(eval("-0b000000000010"), -2)
+        self.assertEqual(eval("0o777"), 511)
+        self.assertEqual(eval("-0o0000010"), -8)
 
     def test_unary_minus(self):
         # Verify treatment of unary minus on negative numbers SF bug #660455
diff --git a/Lib/test/test_hexoct.py b/Lib/test/test_hexoct.py
deleted file mode 100644
index f71dbe0..0000000
--- a/Lib/test/test_hexoct.py
+++ /dev/null
@@ -1,116 +0,0 @@
-"""Test correct treatment of hex/oct constants.
-
-This is complex because of changes due to PEP 237.
-"""
-
-import sys
-platform_long_is_32_bits = sys.maxint == 2147483647
-
-import unittest
-from test import test_support
-
-import warnings
-warnings.filterwarnings("ignore", "hex/oct constants", FutureWarning,
-                        "<string>")
-
-class TextHexOct(unittest.TestCase):
-
-    def test_hex_baseline(self):
-        # Baseline tests
-        self.assertEqual(0x0, 0)
-        self.assertEqual(0x10, 16)
-        if platform_long_is_32_bits:
-            self.assertEqual(0x7fffffff, 2147483647)
-        else:
-            self.assertEqual(0x7fffffffffffffff, 9223372036854775807)
-        # Ditto with a minus sign and parentheses
-        self.assertEqual(-(0x0), 0)
-        self.assertEqual(-(0x10), -16)
-        if platform_long_is_32_bits:
-            self.assertEqual(-(0x7fffffff), -2147483647)
-        else:
-            self.assertEqual(-(0x7fffffffffffffff), -9223372036854775807)
-        # Ditto with a minus sign and NO parentheses
-        self.assertEqual(-0x0, 0)
-        self.assertEqual(-0x10, -16)
-        if platform_long_is_32_bits:
-            self.assertEqual(-0x7fffffff, -2147483647)
-        else:
-            self.assertEqual(-0x7fffffffffffffff, -9223372036854775807)
-
-    def test_hex_unsigned(self):
-        if platform_long_is_32_bits:
-            # Positive constants
-            self.assertEqual(0x80000000, 2147483648L)
-            self.assertEqual(0xffffffff, 4294967295L)
-            # Ditto with a minus sign and parentheses
-            self.assertEqual(-(0x80000000), -2147483648L)
-            self.assertEqual(-(0xffffffff), -4294967295L)
-            # Ditto with a minus sign and NO parentheses
-            # This failed in Python 2.2 through 2.2.2 and in 2.3a1
-            self.assertEqual(-0x80000000, -2147483648L)
-            self.assertEqual(-0xffffffff, -4294967295L)
-        else:
-            # Positive constants
-            self.assertEqual(0x8000000000000000, 9223372036854775808L)
-            self.assertEqual(0xffffffffffffffff, 18446744073709551615L)
-            # Ditto with a minus sign and parentheses
-            self.assertEqual(-(0x8000000000000000), -9223372036854775808L)
-            self.assertEqual(-(0xffffffffffffffff), -18446744073709551615L)
-            # Ditto with a minus sign and NO parentheses
-            # This failed in Python 2.2 through 2.2.2 and in 2.3a1
-            self.assertEqual(-0x8000000000000000, -9223372036854775808L)
-            self.assertEqual(-0xffffffffffffffff, -18446744073709551615L)
-
-    def test_oct_baseline(self):
-        # Baseline tests
-        self.assertEqual(00, 0)
-        self.assertEqual(020, 16)
-        if platform_long_is_32_bits:
-            self.assertEqual(017777777777, 2147483647)
-        else:
-            self.assertEqual(0777777777777777777777, 9223372036854775807)
-        # Ditto with a minus sign and parentheses
-        self.assertEqual(-(00), 0)
-        self.assertEqual(-(020), -16)
-        if platform_long_is_32_bits:
-            self.assertEqual(-(017777777777), -2147483647)
-        else:
-            self.assertEqual(-(0777777777777777777777), -9223372036854775807)
-        # Ditto with a minus sign and NO parentheses
-        self.assertEqual(-00, 0)
-        self.assertEqual(-020, -16)
-        if platform_long_is_32_bits:
-            self.assertEqual(-017777777777, -2147483647)
-        else:
-            self.assertEqual(-0777777777777777777777, -9223372036854775807)
-
-    def test_oct_unsigned(self):
-        if platform_long_is_32_bits:
-            # Positive constants
-            self.assertEqual(020000000000, 2147483648L)
-            self.assertEqual(037777777777, 4294967295L)
-            # Ditto with a minus sign and parentheses
-            self.assertEqual(-(020000000000), -2147483648L)
-            self.assertEqual(-(037777777777), -4294967295L)
-            # Ditto with a minus sign and NO parentheses
-            # This failed in Python 2.2 through 2.2.2 and in 2.3a1
-            self.assertEqual(-020000000000, -2147483648L)
-            self.assertEqual(-037777777777, -4294967295L)
-        else:
-            # Positive constants
-            self.assertEqual(01000000000000000000000, 9223372036854775808L)
-            self.assertEqual(01777777777777777777777, 18446744073709551615L)
-            # Ditto with a minus sign and parentheses
-            self.assertEqual(-(01000000000000000000000), -9223372036854775808L)
-            self.assertEqual(-(01777777777777777777777), -18446744073709551615L)
-            # Ditto with a minus sign and NO parentheses
-            # This failed in Python 2.2 through 2.2.2 and in 2.3a1
-            self.assertEqual(-01000000000000000000000, -9223372036854775808L)
-            self.assertEqual(-01777777777777777777777, -18446744073709551615L)
-
-def test_main():
-    test_support.run_unittest(TextHexOct)
-
-if __name__ == "__main__":
-    test_main()
diff --git a/Lib/test/test_int_literal.py b/Lib/test/test_int_literal.py
new file mode 100644
index 0000000..f4f08ac
--- /dev/null
+++ b/Lib/test/test_int_literal.py
@@ -0,0 +1,191 @@
+"""Test correct treatment of hex/oct constants.
+
+This is complex because of changes due to PEP 237.
+"""
+
+import unittest
+from test import test_support
+
+import warnings
+warnings.filterwarnings("ignore", "hex/oct constants", FutureWarning,
+                        "<string>")
+
+class TextHexOctBin(unittest.TestCase):
+
+    def test_hex_baseline(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0x0, 0X0)
+        self.assertEqual(0x1, 0X1)
+        self.assertEqual(0x123456789abcdef, 0X123456789abcdef)
+        # Baseline tests
+        self.assertEqual(0x0, 0)
+        self.assertEqual(0x10, 16)
+        self.assertEqual(0x7fffffff, 2147483647)
+        self.assertEqual(0x7fffffffffffffff, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x0), 0)
+        self.assertEqual(-(0x10), -16)
+        self.assertEqual(-(0x7fffffff), -2147483647)
+        self.assertEqual(-(0x7fffffffffffffff), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0x0, 0)
+        self.assertEqual(-0x10, -16)
+        self.assertEqual(-0x7fffffff, -2147483647)
+        self.assertEqual(-0x7fffffffffffffff, -9223372036854775807)
+
+    def test_hex_unsigned(self):
+        # Positive constants
+        self.assertEqual(0x80000000, 2147483648L)
+        self.assertEqual(0xffffffff, 4294967295L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x80000000), -2147483648L)
+        self.assertEqual(-(0xffffffff), -4294967295L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0x80000000, -2147483648L)
+        self.assertEqual(-0xffffffff, -4294967295L)
+
+        # Positive constants
+        self.assertEqual(0x8000000000000000, 9223372036854775808L)
+        self.assertEqual(0xffffffffffffffff, 18446744073709551615L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x8000000000000000), -9223372036854775808L)
+        self.assertEqual(-(0xffffffffffffffff), -18446744073709551615L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0x8000000000000000, -9223372036854775808L)
+        self.assertEqual(-0xffffffffffffffff, -18446744073709551615L)
+
+    def test_oct_baseline(self):
+        # Baseline tests
+        self.assertEqual(00, 0)
+        self.assertEqual(020, 16)
+        self.assertEqual(017777777777, 2147483647)
+        self.assertEqual(0777777777777777777777, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(00), 0)
+        self.assertEqual(-(020), -16)
+        self.assertEqual(-(017777777777), -2147483647)
+        self.assertEqual(-(0777777777777777777777), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-00, 0)
+        self.assertEqual(-020, -16)
+        self.assertEqual(-017777777777, -2147483647)
+        self.assertEqual(-0777777777777777777777, -9223372036854775807)
+
+    def test_oct_baseline_new(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0o0, 0O0)
+        self.assertEqual(0o1, 0O1)
+        self.assertEqual(0o1234567, 0O1234567)
+        # Baseline tests
+        self.assertEqual(0o0, 0)
+        self.assertEqual(0o20, 16)
+        self.assertEqual(0o17777777777, 2147483647)
+        self.assertEqual(0o777777777777777777777, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o0), 0)
+        self.assertEqual(-(0o20), -16)
+        self.assertEqual(-(0o17777777777), -2147483647)
+        self.assertEqual(-(0o777777777777777777777), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0o0, 0)
+        self.assertEqual(-0o20, -16)
+        self.assertEqual(-0o17777777777, -2147483647)
+        self.assertEqual(-0o777777777777777777777, -9223372036854775807)
+
+    def test_oct_unsigned(self):
+        # Positive constants
+        self.assertEqual(020000000000, 2147483648L)
+        self.assertEqual(037777777777, 4294967295L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(020000000000), -2147483648L)
+        self.assertEqual(-(037777777777), -4294967295L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-020000000000, -2147483648L)
+        self.assertEqual(-037777777777, -4294967295L)
+
+        # Positive constants
+        self.assertEqual(01000000000000000000000, 9223372036854775808L)
+        self.assertEqual(01777777777777777777777, 18446744073709551615L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(01000000000000000000000), -9223372036854775808L)
+        self.assertEqual(-(01777777777777777777777), -18446744073709551615L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-01000000000000000000000, -9223372036854775808L)
+        self.assertEqual(-01777777777777777777777, -18446744073709551615L)
+
+    def test_oct_unsigned_new(self):
+        # Positive constants
+        self.assertEqual(0o20000000000, 2147483648L)
+        self.assertEqual(0o37777777777, 4294967295L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o20000000000), -2147483648L)
+        self.assertEqual(-(0o37777777777), -4294967295L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0o20000000000, -2147483648L)
+        self.assertEqual(-0o37777777777, -4294967295L)
+
+        # Positive constants
+        self.assertEqual(0o1000000000000000000000, 9223372036854775808L)
+        self.assertEqual(0o1777777777777777777777, 18446744073709551615L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o1000000000000000000000), -9223372036854775808L)
+        self.assertEqual(-(0o1777777777777777777777), -18446744073709551615L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0o1000000000000000000000, -9223372036854775808L)
+        self.assertEqual(-0o1777777777777777777777, -18446744073709551615L)
+
+    def test_bin_baseline(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0b0, 0B0)
+        self.assertEqual(0b1, 0B1)
+        self.assertEqual(0b10101010101, 0B10101010101)
+        # Baseline tests
+        self.assertEqual(0b0, 0)
+        self.assertEqual(0b10000, 16)
+        self.assertEqual(0b1111111111111111111111111111111, 2147483647)
+        self.assertEqual(0b111111111111111111111111111111111111111111111111111111111111111, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b0), 0)
+        self.assertEqual(-(0b10000), -16)
+        self.assertEqual(-(0b1111111111111111111111111111111), -2147483647)
+        self.assertEqual(-(0b111111111111111111111111111111111111111111111111111111111111111), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0b0, 0)
+        self.assertEqual(-0b10000, -16)
+        self.assertEqual(-0b1111111111111111111111111111111, -2147483647)
+        self.assertEqual(-0b111111111111111111111111111111111111111111111111111111111111111, -9223372036854775807)
+
+    def test_bin_unsigned(self):
+        # Positive constants
+        self.assertEqual(0b10000000000000000000000000000000, 2147483648L)
+        self.assertEqual(0b11111111111111111111111111111111, 4294967295L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b10000000000000000000000000000000), -2147483648L)
+        self.assertEqual(-(0b11111111111111111111111111111111), -4294967295L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0b10000000000000000000000000000000, -2147483648L)
+        self.assertEqual(-0b11111111111111111111111111111111, -4294967295L)
+
+        # Positive constants
+        self.assertEqual(0b1000000000000000000000000000000000000000000000000000000000000000, 9223372036854775808L)
+        self.assertEqual(0b1111111111111111111111111111111111111111111111111111111111111111, 18446744073709551615L)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b1000000000000000000000000000000000000000000000000000000000000000), -9223372036854775808L)
+        self.assertEqual(-(0b1111111111111111111111111111111111111111111111111111111111111111), -18446744073709551615L)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0b1000000000000000000000000000000000000000000000000000000000000000, -9223372036854775808L)
+        self.assertEqual(-0b1111111111111111111111111111111111111111111111111111111111111111, -18446744073709551615L)
+
+def test_main():
+    test_support.run_unittest(TextHexOctBin)
+
+if __name__ == "__main__":
+    test_main()
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 46ed713..afa1b75 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -1465,14 +1465,27 @@
 	while (*str != '\0' && isspace(Py_CHARMASK(*str)))
 		str++;
 	if (base == 0) {
+		/* No base given.  Deduce the base from the contents
+		   of the string */
 		if (str[0] != '0')
 			base = 10;
 		else if (str[1] == 'x' || str[1] == 'X')
 			base = 16;
+		else if (str[1] == 'o' || str[1] == 'O')
+			base = 8;
+		else if (str[1] == 'b' || str[1] == 'B')
+			base = 2;
 		else
+			/* "old" (C-style) octal literal, still valid in
+			   2.x, although illegal in 3.x */
 			base = 8;
 	}
-	if (base == 16 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
+	/* Whether or not we were deducing the base, skip leading chars
+	   as needed */
+	if (str[0] == '0' &&
+	    ((base == 16 && (str[1] == 'x' || str[1] == 'X')) ||
+	     (base == 8  && (str[1] == 'o' || str[1] == 'O')) ||
+	     (base == 2  && (str[1] == 'b' || str[1] == 'B'))))
 		str += 2;
 
 	start = str;
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index 1314f5f..6df3005 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1335,7 +1335,7 @@
 	/* Number */
 	if (isdigit(c)) {
 		if (c == '0') {
-			/* Hex or octal -- maybe. */
+			/* Hex, octal or binary -- maybe. */
 			c = tok_nextc(tok);
 			if (c == '.')
 				goto fraction;
@@ -1356,6 +1356,30 @@
 					c = tok_nextc(tok);
 				} while (isxdigit(c));
 			}
+                        else if (c == 'o' || c == 'O') {
+				/* Octal */
+				c = tok_nextc(tok);
+				if (c < '0' || c > '8') {
+					tok->done = E_TOKEN;
+					tok_backup(tok, c);
+					return ERRORTOKEN;
+				}
+				do {
+					c = tok_nextc(tok);
+				} while ('0' <= c && c < '8');
+			}
+			else if (c == 'b' || c == 'B') {
+				/* Binary */
+				c = tok_nextc(tok);
+				if (c != '0' && c != '1') {
+					tok->done = E_TOKEN;
+					tok_backup(tok, c);
+					return ERRORTOKEN;
+				}
+				do {
+					c = tok_nextc(tok);
+				} while (c == '0' || c == '1');
+			}
 			else {
 				int found_decimal = 0;
 				/* Octal; c is first char of it */
diff --git a/Python/mystrtoul.c b/Python/mystrtoul.c
index cb3c012..ebd468c 100644
--- a/Python/mystrtoul.c
+++ b/Python/mystrtoul.c
@@ -83,9 +83,9 @@
 **		This is a general purpose routine for converting
 **		an ascii string to an integer in an arbitrary base.
 **		Leading white space is ignored.  If 'base' is zero
-**		it looks for a leading 0, 0x or 0X to tell which
-**		base.  If these are absent it defaults to 10.
-**		Base must be 0 or between 2 and 36 (inclusive).
+**		it looks for a leading 0, 0b, 0B, 0o, 0O, 0x or 0X
+**		to tell which base.  If these are absent it defaults
+**		to 10. Base must be 0 or between 2 and 36 (inclusive).
 **		If 'ptr' is non-NULL it will contain a pointer to
 **		the end of the scan.
 **		Errors due to bad pointers will probably result in
@@ -104,7 +104,7 @@
 
 	/* check for leading 0 or 0x for auto-base or base 16 */
 	switch (base) {
-	case 0:		/* look for leading 0, 0x or 0X */
+	case 0:		/* look for leading 0, 0b, 0o or 0x */
 		if (*str == '0') {
 			++str;
 			if (*str == 'x' || *str == 'X') {
@@ -116,14 +116,62 @@
 				}
 				++str;
 				base = 16;
-			}
-			else
+			} else if (*str == 'o' || *str == 'O') {
+				/* there must be at least one digit after 0o */
+				if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {
+					if (ptr)
+						*ptr = str;
+					return 0;
+				}
+				++str;
 				base = 8;
+			} else if (*str == 'b' || *str == 'B') {
+				/* there must be at least one digit after 0b */
+				if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {
+					if (ptr)
+						*ptr = str;
+					return 0;
+				}
+				++str;
+				base = 2;
+			} else {
+				base = 8;
+			}
 		}
 		else
 			base = 10;
 		break;
 
+	case 2:	/* skip leading 0b or 0B */
+		if (*str == '0') {
+			++str;
+			if (*str == 'b' || *str == 'B') {
+				/* there must be at least one digit after 0b */
+				if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) {
+					if (ptr)
+						*ptr = str;
+					return 0;
+				}
+				++str;
+			}
+		}
+		break;
+
+	case 8:	/* skip leading 0o or 0O */
+		if (*str == '0') {
+			++str;
+			if (*str == 'o' || *str == 'O') {
+				/* there must be at least one digit after 0o */
+				if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) {
+					if (ptr)
+						*ptr = str;
+					return 0;
+				}
+				++str;
+			}
+		}
+		break;
+
 	case 16:	/* skip leading 0x or 0X */
 		if (*str == '0') {
 			++str;