diff --git a/src/mu-msg-fields.c b/src/mu-msg-fields.c
index 7d7439e5..4d855971 100644
--- a/src/mu-msg-fields.c
+++ b/src/mu-msg-fields.c
@@ -46,8 +46,9 @@ enum _FieldFlags {
 	FLAG_XAPIAN_BOOLEAN      = 1 << 6, /* use 'add_boolean_prefix'
 					    * for Xapian queries */
 	FLAG_XAPIAN_PREFIX_ONLY  = 1 << 7, /* whether this fields
-					    * matches only in queries
-					    * when a prefix is used */
+					    * matches only when the
+					    * prefix is explicitly
+					    * included */
 	FLAG_NORMALIZE	         = 1 << 8, /* field needs flattening for
 					    * case/accents */
 	FLAG_DONT_CACHE          = 1 << 9  /* don't cache this field in
@@ -150,8 +151,7 @@ static const MuMsgField FIELD_DATA[] = {
 		MU_MSG_FIELD_TYPE_STRING,
 		"maildir", 'm', 'M',
 		FLAG_GMIME | FLAG_XAPIAN_TERM | FLAG_XAPIAN_VALUE |
-		FLAG_NORMALIZE | FLAG_XAPIAN_ESCAPE |
-		FLAG_XAPIAN_BOOLEAN | FLAG_XAPIAN_PREFIX_ONLY
+		FLAG_NORMALIZE | FLAG_XAPIAN_ESCAPE | FLAG_XAPIAN_PREFIX_ONLY
 	},
 
 	{
@@ -175,7 +175,7 @@ static const MuMsgField FIELD_DATA[] = {
 		MU_MSG_FIELD_TYPE_STRING,
 		"subject", 's', 'S',
 		FLAG_GMIME | FLAG_XAPIAN_INDEX | FLAG_XAPIAN_VALUE |
-		FLAG_NORMALIZE
+		FLAG_XAPIAN_TERM | FLAG_NORMALIZE
 	},
 
 	{