diff --git a/lib/regexp-fields.cc b/lib/regexp-fields.cc
index 8e740a81..9dcf9732 100644
--- a/lib/regexp-fields.cc
+++ b/lib/regexp-fields.cc
@@ -158,8 +158,14 @@ RegexpFieldProcessor::operator() (const std::string & str)
     } else {
 	/* TODO replace this with a nicer API level triggering of
 	 * phrase parsing, when possible */
-	std::string quoted='"' + str + '"';
-	return parser.parse_query (quoted, NOTMUCH_QUERY_PARSER_FLAGS, term_prefix);
+	std::string query_str;
+
+	if (str.find (' ') != std::string::npos)
+	    query_str = '"' + str + '"';
+	else
+	    query_str = str;
+
+	return parser.parse_query (query_str, NOTMUCH_QUERY_PARSER_FLAGS, term_prefix);
     }
 }
 #endif
diff --git a/test/T650-regexp-query.sh b/test/T650-regexp-query.sh
index 1db6a76b..61739e87 100755
--- a/test/T650-regexp-query.sh
+++ b/test/T650-regexp-query.sh
@@ -12,12 +12,10 @@ fi
 notmuch search --output=messages from:cworth > cworth.msg-ids
 
 test_begin_subtest "xapian wildcard search for from:"
-test_subtest_known_broken
 notmuch search --output=messages 'from:cwo*' > OUTPUT
 test_expect_equal_file cworth.msg-ids OUTPUT
 
 test_begin_subtest "xapian wildcard search for subject:"
-test_subtest_known_broken
 test_expect_equal $(notmuch count 'subject:count*') 1
 
 test_begin_subtest "regexp from search, case sensitive"