diff -r 7f49af7046e4 -r ad5e26259e44 Lib/lib2to3/pgen2/tokenize.py
--- a/Lib/lib2to3/pgen2/tokenize.py	Tue Dec 15 11:29:59 2015 +0100
+++ b/Lib/lib2to3/pgen2/tokenize.py	Tue Dec 22 01:56:35 2015 -0600
@@ -95,9 +95,9 @@
 Token = Ignore + PlainToken
 
 # First (or only) line of ' or " string.
-ContStr = group(r"[uUbB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
+ContStr = group(r"[uUbB]?[rR]?[bB]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
                 group("'", r'\\\r?\n'),
-                r'[uUbB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
+                r'[uUbB]?[rR]?[bB]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
                 group('"', r'\\\r?\n'))
 PseudoExtras = group(r'\\\r?\n', Comment, Triple)
 PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
@@ -111,6 +111,7 @@
             "b'''": single3prog, 'b"""': double3prog,
             "ur'''": single3prog, 'ur"""': double3prog,
             "br'''": single3prog, 'br"""': double3prog,
+            "rb'''": single3prog, 'rb"""': double3prog,
             "R'''": single3prog, 'R"""': double3prog,
             "U'''": single3prog, 'U"""': double3prog,
             "B'''": single3prog, 'B"""': double3prog,
@@ -120,6 +121,9 @@
             "bR'''": single3prog, 'bR"""': double3prog,
             "Br'''": single3prog, 'Br"""': double3prog,
             "BR'''": single3prog, 'BR"""': double3prog,
+            "rB'''": single3prog, 'rB"""': double3prog,
+            "Rb'''": single3prog, 'Rb"""': double3prog,
+            "RB'''": single3prog, 'RB"""': double3prog,
             'r': None, 'R': None,
             'u': None, 'U': None,
             'b': None, 'B': None}
@@ -132,7 +136,9 @@
           "ur'''", 'ur"""', "Ur'''", 'Ur"""',
           "uR'''", 'uR"""', "UR'''", 'UR"""',
           "br'''", 'br"""', "Br'''", 'Br"""',
-          "bR'''", 'bR"""', "BR'''", 'BR"""',):
+          "bR'''", 'bR"""', "BR'''", 'BR"""',
+          "rb'''", 'rb"""', "Rb'''", 'Rb"""',
+          "rB'''", 'rB"""', "RB'''", 'RB"""',):
     triple_quoted[t] = t
 single_quoted = {}
 for t in ("'", '"',
@@ -142,7 +148,9 @@
           "ur'", 'ur"', "Ur'", 'Ur"',
           "uR'", 'uR"', "UR'", 'UR"',
           "br'", 'br"', "Br'", 'Br"',
-          "bR'", 'bR"', "BR'", 'BR"', ):
+          "bR'", 'bR"', "BR'", 'BR"',
+          "rb'", 'rb"', "Rb'", 'Rb"',
+          "rB'", 'rB"', "RB'", 'RB"',):
     single_quoted[t] = t
 
 tabsize = 8