Uglification fails when using webpack -p

[centromere]

When executing webpack -p I get the following error:

$ webpack -p
  [87] ./src/App/Routes.purs 1.44 kB {0} [built]
  [88] ./src/App/State.purs 727 bytes {0} [built]
  [91] ./~/preact-compat/dist/preact-compat.es.js 17 kB {0} [built]
 [115] ./src/App/Events.purs 1.27 kB {0} [built]
 [117] ./~/preact-compat/server.js 230 bytes {0} [built]
 [153] ./support/entry.js 355 bytes {0} [built]
 [221] ./~/prop-types/index.js 1.08 kB {0} [built]
 [278] ./src/App/Config.purs 185 bytes {0} [built]
 [279] ./src/App/View/Homepage.purs 2.1 kB {0} [built]
 [280] ./src/App/View/Layout.purs 8.74 kB {0} [built]
 [281] ./src/App/View/NotFound.purs 754 bytes {0} [built]
 [282] ./src/Main.purs 2.74 kB {0} [built]
 [285] (webpack)/buildin/module.js 517 bytes {0} [built]
 [286] ./src/App/Config.js 175 bytes {0} [built]
 [287] multi ./support/entry.js 28 bytes {0} [built]
    + 273 hidden modules

WARNING in            Src   Lib   All
Warnings   0     0     0  
Errors     0     0     0  

ERROR in bundle.js from UglifyJs
Unexpected token: name (ClientEntry) [bundle.js:24180,4]

It's due to the fact that entry.js is written in ES6, but uglify-js doesn't support that yet.