diff --git a/mysql-test/r/mysql.result b/mysql-test/r/mysql.result
index 7dbff4beca5d91566fd71ee0bf3a086ac1fd1816..1053b1918fb03b5047231eb23a09b117d6583972 100644
--- a/mysql-test/r/mysql.result
+++ b/mysql-test/r/mysql.result
@@ -76,6 +76,16 @@ c_cp932
 | >a   <               | 0123456789 |      4 | 
 | >abcd<               |            |      4 | 
 +----------------------+------------+--------+
++-------------------+
+| __tañgè Ñãmé      |
++-------------------+
+| John Doe          | 
++-------------------+
++-------------------+
+| John Doe          |
++-------------------+
+| __tañgè Ñãmé      | 
++-------------------+
 +------+------+---------------------------+
 | i    | j    | k                         |
 +------+------+---------------------------+
diff --git a/mysql-test/t/mysql.test b/mysql-test/t/mysql.test
index 9e3eabf474be536e7e4ee7597bbe87603768152e..f3296e6f7068a58c76f82b02331ac52487d35551 100644
--- a/mysql-test/t/mysql.test
+++ b/mysql-test/t/mysql.test
@@ -62,6 +62,12 @@ drop table t1;
 #
 --exec $MYSQL -t test -e "create table t1 (col1 binary(4), col2 varchar(10), col3 int); insert into t1 values ('a', 'b', 123421),('a ', '0123456789', 4), ('abcd', '', 4); select concat('>',col1,'<'), col2, col3 from t1; drop table t1;" 2>&1
 
+#
+# Bug#17939 Wrong table format when using UTF8 strings
+#
+--exec $MYSQL --default-character-set=utf8 --table -e "SELECT 'John Doe' as '__tañgè Ñãmé'" 2>&1
+--exec $MYSQL --default-character-set=utf8 --table -e "SELECT '__tañgè Ñãmé' as 'John Doe'" 2>&1
+
 #
 # Bug#18265 -- mysql client: No longer right-justifies numeric columns
 #
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index eb78f4fbdae453782658f06982c320f40d72aca9..4469bbacf909023f20e4efd56ba6d5596224b760 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -4277,7 +4277,7 @@ ST_FIELD_INFO triggers_fields_info[]=
 ST_FIELD_INFO variables_fields_info[]=
 {
   {"Variable_name", 80, MYSQL_TYPE_STRING, 0, 0, "Variable_name"},
-  {"Value", 255, MYSQL_TYPE_STRING, 0, 0, "Value"},
+  {"Value", FN_REFLEN, MYSQL_TYPE_STRING, 0, 0, "Value"},
   {0, 0, MYSQL_TYPE_STRING, 0, 0, 0}
 };