diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index 8869604b128..bcf9cc77519 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -715,3 +715,10 @@ lily
 river
 drop table t1;
 deallocate prepare stmt;
+CREATE TABLE t1 (id int, s char(5) CHARACTER SET ucs2 COLLATE ucs2_unicode_ci);
+INSERT INTO t1 VALUES (1, 'ZZZZZ'), (1, 'ZZZ'), (2, 'ZZZ'), (2, 'ZZZZZ');
+SELECT id, MIN(s) FROM t1 GROUP BY id;
+id	MIN(s)
+1	ZZZ
+2	ZZZ
+DROP TABLE t1;
diff --git a/mysql-test/t/ctype_ucs.test b/mysql-test/t/ctype_ucs.test
index 2cbabf88ee0..a4d4d1846a7 100644
--- a/mysql-test/t/ctype_ucs.test
+++ b/mysql-test/t/ctype_ucs.test
@@ -451,4 +451,16 @@ execute stmt using @param1;
 select utext from t1 where utext like '%%';
 drop table t1;
 deallocate prepare stmt;
+
+#
+# Bug #20076: server crashes for a query with GROUP BY if MIN/MAX aggregation
+#             over a 'ucs2' field uses a temporary table 
+#
+
+CREATE TABLE t1 (id int, s char(5) CHARACTER SET ucs2 COLLATE ucs2_unicode_ci);
+INSERT INTO t1 VALUES (1, 'ZZZZZ'), (1, 'ZZZ'), (2, 'ZZZ'), (2, 'ZZZZZ');
+
+SELECT id, MIN(s) FROM t1 GROUP BY id;
+
+DROP TABLE t1;
 # End of 4.1 tests
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 4b522cf06fa..0b9b10d05d4 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -930,7 +930,6 @@ Item_sum_hybrid::min_max_update_str_field()
 
   if (!args[0]->null_value)
   {
-    res_str->strip_sp();
     result_field->val_str(&tmp_value);
 
     if (result_field->is_null() ||