diff --git a/mysql-test/include/ctype_numconv.inc b/mysql-test/include/ctype_numconv.inc
index 06a9107e963..c4a39879947 100644
--- a/mysql-test/include/ctype_numconv.inc
+++ b/mysql-test/include/ctype_numconv.inc
@@ -1635,12 +1635,7 @@ CREATE TABLE t1 (a MEDIUMINT NULL) ENGINE=MYISAM;
 INSERT INTO t1 VALUES (1234567);
 SELECT GROUP_CONCAT(IFNULL(a,'')) FROM t1;
 SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
-if (`SELECT @@character_set_connection != 'ucs2'`)
-{
-  # Temporarily disable for ucs2
-  # For details, see Bug#55744 GROUP_CONCAT + CASE + ucs return garbage
-  SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
-}
+SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
 --enable_metadata
 SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
 --disable_metadata
diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index 1215eb1db02..c2fb90ecfa6 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -3853,6 +3853,9 @@ GROUP_CONCAT(IFNULL(a,''))
 SELECT GROUP_CONCAT(IF(a,a,'')) FROM t1;
 GROUP_CONCAT(IF(a,a,''))
 1234567
+SELECT GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END) FROM t1;
+GROUP_CONCAT(CASE WHEN a THEN a ELSE '' END)
+1234567
 SELECT COALESCE(a,'') FROM t1 GROUP BY 1;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					COALESCE(a,'')	253	9	7	Y	0	31	8
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index b7aad733e67..b04ec105468 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -3029,6 +3029,14 @@ void Item_func_case::fix_length_and_dec()
   {
     if (agg_arg_charsets_for_string_result(collation, agg, nagg))
       return;
+    /*
+      Copy all THEN and ELSE items back to args[] array.
+      Some of the items might have been changed to Item_func_conv_charset.
+    */
+    for (nagg= 0 ; nagg < ncases / 2 ; nagg++)
+      args[nagg * 2 + 1]= agg[nagg];
+    if (else_expr_num != -1)
+      args[else_expr_num]= agg[nagg++];
   }
   else
     collation.set_numeric();