diff --git a/src/calmjs/parse/lexers/es2015.py b/src/calmjs/parse/lexers/es2015.py
index 1dce694..62fbc54 100644
--- a/src/calmjs/parse/lexers/es2015.py
+++ b/src/calmjs/parse/lexers/es2015.py
@@ -50,6 +50,27 @@ class Lexer(ES5Lexer):
         'TEMPLATE_NOSUB', 'TEMPLATE_HEAD', 'TEMPLATE_MIDDLE', 'TEMPLATE_TAIL',
     )
 
+    t_NUMBER = r"""
+    (?: 0[bB][01]+                     # binary_integer_literal
+     |  0[oO][0-7]+                    # or octal_integer_literal
+     |  0[xX][0-9a-fA-F]+              # or hex_integer_literal
+     |  0[0-7]+                        # or legacy_octal_integer_literal
+     |  (?:                            # or decimal_literal
+            (?:0|[1-9][0-9]*)          # decimal_integer_literal
+            \.                         # dot
+            [0-9]*                     # decimal_digits_opt
+            (?:[eE][+-]?[0-9]+)?       # exponent_part_opt
+         |
+            \.                         # dot
+            [0-9]+                     # decimal_digits
+            (?:[eE][+-]?[0-9]+)?       # exponent_part_opt
+         |
+            (?:0|[1-9][0-9]*)          # decimal_integer_literal
+            (?:[eE][+-]?[0-9]+)?       # exponent_part_opt
+         )
+    )
+    """
+
     template = r"""
     (?:(?:`|})                         # opening ` or }
         (?: [^`\\]                     # no \, or `
diff --git a/src/calmjs/parse/tests/lexer.py b/src/calmjs/parse/tests/lexer.py
index a791750..ba427a0 100644
--- a/src/calmjs/parse/tests/lexer.py
+++ b/src/calmjs/parse/tests/lexer.py
@@ -501,6 +501,10 @@
         ('function *gen() { yield 1 }',
          ['FUNCTION function', 'MULT *', 'ID gen', 'LPAREN (', 'RPAREN )',
           'LBRACE {', 'YIELD yield', 'NUMBER 1', 'RBRACE }']),
+    ), (
+        'es2015_numbers',
+        (('0b1011 0B1101 0o755 0O644'),
+         ['NUMBER 0b1011', 'NUMBER 0B1101', 'NUMBER 0o755', 'NUMBER 0O644']),
     ), (
         'punctuators',
         ('=> ...',