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;