diff --git a/src/tools/mc.py b/src/tools/mc.py
index 9992c36c1..d8b970194 100644
--- a/src/tools/mc.py
+++ b/src/tools/mc.py
@@ -34,7 +34,7 @@ feature('mc-set-customer-bit', ['no', 'yes'], ['free'])
 
 flags('mc.compile', 'MCFLAGS', ['<mc-input-encoding>ansi'], ['-a'])
 flags('mc.compile', 'MCFLAGS', ['<mc-input-encoding>unicode'], ['-u'])
-flags('mc.compile', 'MCFLAGS', ['<mc-output-encoding>ansi'], '-A')
+flags('mc.compile', 'MCFLAGS', ['<mc-output-encoding>ansi'], ['-A'])
 flags('mc.compile', 'MCFLAGS', ['<mc-output-encoding>unicode'], ['-U'])
 flags('mc.compile', 'MCFLAGS', ['<mc-set-customer-bit>no'], [])
 flags('mc.compile', 'MCFLAGS', ['<mc-set-customer-bit>yes'], ['-c'])