diff --git a/Lib/tokenize.py b/Lib/tokenize.py
index e94d7b9..9ea57b6 100644
--- a/Lib/tokenize.py
+++ b/Lib/tokenize.py
@@ -49,10 +49,11 @@
 Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
 Name = r'[a-zA-Z_]\w*'
 
-Hexnumber = r'0[xX][\da-fA-F]*[lL]?'
-Octnumber = r'0[0-7]*[lL]?'
-Decnumber = r'[1-9]\d*[lL]?'
-Intnumber = group(Hexnumber, Octnumber, Decnumber)
+Hexnumber = r'0[xX][\da-fA-F]*'
+Binnumber = r'0[bB][01]*'
+Octnumber = r'0[oO][0-7]*'
+Decnumber = r'(?:0+|[1-9]\d*)'
+Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
 Exponent = r'[eE][-+]?\d+'
 Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent)
 Expfloat = r'\d+' + Exponent