es6-module-transpiler Esprima error

gistfile1.txt

Line 2: Unexpected token => Error: Line 2: Unexpected token =>
    at throwError (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2038:21)
    at throwUnexpected (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2100:9)
    at parsePrimaryExpression (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2554:16)
    at /Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:5120:38
    at trackLeftHandSideExpressionAllowCall (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:5022:61)
    at parsePostfixExpression (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2673:20)
    at /Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:5120:38
    at parseUnaryExpression (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2737:16)
    at /Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:5120:38
    at parseBinaryExpression (/Users/xtian/Projects/es6-test/node_modules/broccoli-es6-concatenator/node_modules/es6-module-transpiler/node_modules/esprima/esprima.js:2825:16)