diff --git a/phsource/mbrola/ar1 b/phsource/mbrola/ar1
index bdd90e81..5a6bd696 100644
--- a/phsource/mbrola/ar1
+++ b/phsource/mbrola/ar1
@@ -33,6 +33,8 @@ volume 50
 0   m   m     100  n    m
 0   m   NULL  0    m
 0   n   NULL  0    n
+4   ?   NULL  0    _
+64  ?   NULL  0    _
 0   ?   NULL  0    ?
 0   p   NULL  0    p
 0   q   NULL  0    q