--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -364,21 +364,17 @@ def eme(value, fmp4):
     if enabled and not fmp4:
         die('Encrypted Media Extension support requires '
             'Fragmented MP4 support')
     if enabled:
         return True
 
 @depends('--enable-eme')
 def eme_modules(value):
-    # Theoretically, we could pass `value` directly when it is a
-    # PositiveOptionValue, but somehow, the JSON serialization in configure.py
-    # outputs inconsistent data in some cases when we do (a closing bracket
-    # without an opening one).
-    return list(value) if value else []
+    return value
 
 set_config('MOZ_EME', eme)
 set_define('MOZ_EME', eme)
 set_config('MOZ_EME_MODULES', eme_modules)
 
 option(name='--enable-chrome-format',
        help='Select FORMAT of chrome files during packaging.',
        nargs=1,