diff --git a/include/my_sys.h b/include/my_sys.h
index 4f7e75a836e..7218f91cccd 100644
--- a/include/my_sys.h
+++ b/include/my_sys.h
@@ -879,6 +879,8 @@ extern CHARSET_INFO *get_charset(uint cs_number, myf flags);
 extern CHARSET_INFO *get_charset_by_name(const char *cs_name, myf flags);
 extern CHARSET_INFO *get_charset_by_csname(const char *cs_name,
 					   uint cs_flags, myf my_flags);
+extern CHARSET_INFO *get_compatible_charset_with_ctype(CHARSET_INFO
+                                                       *original_cs);
 extern void free_charsets(void);
 extern char *get_charsets_dir(char *buf);
 extern my_bool my_charset_same(CHARSET_INFO *cs1, CHARSET_INFO *cs2);
diff --git a/mysql-test/r/ctype_ucs.result b/mysql-test/r/ctype_ucs.result
index 023267c227c..28e3b50e371 100644
--- a/mysql-test/r/ctype_ucs.result
+++ b/mysql-test/r/ctype_ucs.result
@@ -811,6 +811,12 @@ quote(name)
 ????????
 ????????????????
 drop table bug20536;
+CREATE TABLE t1(a TEXT CHARSET ucs2 COLLATE ucs2_unicode_ci);
+INSERT INTO t1 VALUES('abcd');
+SELECT * FROM t1 WHERE MATCH(a) AGAINST ('+abcd' IN BOOLEAN MODE);
+a
+abcd
+DROP TABLE t1;
 End of 4.1 tests
 CREATE TABLE t1 (a varchar(64) character set ucs2, b decimal(10,3));
 INSERT INTO t1 VALUES ("1.1", 0), ("2.1", 0);
diff --git a/mysql-test/t/ctype_ucs.test b/mysql-test/t/ctype_ucs.test
index bca3a9c3a96..c498f9b9a8d 100644
--- a/mysql-test/t/ctype_ucs.test
+++ b/mysql-test/t/ctype_ucs.test
@@ -547,6 +547,14 @@ select quote(name) from bug20536;
 
 drop table bug20536;
 
+#
+# BUG#31159 - fulltext search on ucs2 column crashes server
+#
+CREATE TABLE t1(a TEXT CHARSET ucs2 COLLATE ucs2_unicode_ci);
+INSERT INTO t1 VALUES('abcd');
+SELECT * FROM t1 WHERE MATCH(a) AGAINST ('+abcd' IN BOOLEAN MODE);
+DROP TABLE t1;
+
 --echo End of 4.1 tests
 
 #
diff --git a/mysys/charset.c b/mysys/charset.c
index 4c3f2d0ab71..d1cca150308 100644
--- a/mysys/charset.c
+++ b/mysys/charset.c
@@ -810,3 +810,43 @@ ulong escape_quotes_for_mysql(CHARSET_INFO *charset_info,
   *to= 0;
   return overflow ? (ulong)~0 : (ulong) (to - to_start);
 }
+
+
+/**
+  @brief Find compatible character set with ctype.
+
+  @param[in] original_cs Original character set
+
+  @note
+    128 my_charset_ucs2_general_uca      ->192 my_charset_utf8_general_uca_ci
+    129 my_charset_ucs2_icelandic_uca_ci ->193 my_charset_utf8_icelandic_uca_ci
+    130 my_charset_ucs2_latvian_uca_ci   ->194 my_charset_utf8_latvian_uca_ci
+    131 my_charset_ucs2_romanian_uca_ci  ->195 my_charset_utf8_romanian_uca_ci
+    132 my_charset_ucs2_slovenian_uca_ci ->196 my_charset_utf8_slovenian_uca_ci
+    133 my_charset_ucs2_polish_uca_ci    ->197 my_charset_utf8_polish_uca_ci
+    134 my_charset_ucs2_estonian_uca_ci  ->198 my_charset_utf8_estonian_uca_ci
+    135 my_charset_ucs2_spanish_uca_ci   ->199 my_charset_utf8_spanish_uca_ci
+    136 my_charset_ucs2_swedish_uca_ci   ->200 my_charset_utf8_swedish_uca_ci
+    137 my_charset_ucs2_turkish_uca_ci   ->201 my_charset_utf8_turkish_uca_ci
+    138 my_charset_ucs2_czech_uca_ci     ->202 my_charset_utf8_czech_uca_ci
+    139 my_charset_ucs2_danish_uca_ci    ->203 my_charset_utf8_danish_uca_ci
+    140 my_charset_ucs2_lithuanian_uca_ci->204 my_charset_utf8_lithuanian_uca_ci
+    141 my_charset_ucs2_slovak_uca_ci    ->205 my_charset_utf8_slovak_uca_ci
+    142 my_charset_ucs2_spanish2_uca_ci  ->206 my_charset_utf8_spanish2_uca_ci
+    143 my_charset_ucs2_roman_uca_ci     ->207 my_charset_utf8_roman_uca_ci
+    144 my_charset_ucs2_persian_uca_ci   ->208 my_charset_utf8_persian_uca_ci
+
+  @return Compatible character set or NULL.
+*/
+
+CHARSET_INFO *get_compatible_charset_with_ctype(CHARSET_INFO *original_cs)
+{
+  CHARSET_INFO *compatible_cs= 0;
+  DBUG_ENTER("get_compatible_charset_with_ctype");
+  if (!strcmp(original_cs->csname, "ucs2") &&
+      (compatible_cs= get_charset(original_cs->number + 64, MYF(0))) &&
+      (!compatible_cs->ctype ||
+       strcmp(original_cs->name + 4, compatible_cs->name + 4)))
+    compatible_cs= 0;
+  DBUG_RETURN(compatible_cs);
+}
diff --git a/sql/item_func.cc b/sql/item_func.cc
index e4d370bbdf2..619736b99ff 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -4939,13 +4939,44 @@ bool Item_func_match::fix_fields(THD *thd, Item **ref)
     my_error(ER_WRONG_ARGUMENTS,MYF(0),"MATCH");
     return TRUE;
   }
-  table=((Item_field *)item)->field->table;
+  /*
+    With prepared statements Item_func_match::fix_fields is called twice.
+    When it is called first time we have original item tree here and add
+    conversion layer for character sets that do not have ctype array a few
+    lines below. When it is called second time, we already have conversion
+    layer in item tree.
+  */
+  table= (item->type() == Item::FIELD_ITEM) ?
+         ((Item_field *)item)->field->table :
+         ((Item_field *)((Item_func_conv *)item)->key_item())->field->table;
   if (!(table->file->table_flags() & HA_CAN_FULLTEXT))
   {
     my_error(ER_TABLE_CANT_HANDLE_FT, MYF(0));
     return 1;
   }
   table->fulltext_searched=1;
+  /* A workaround for ucs2 character set */
+  if (!args[1]->collation.collation->ctype)
+  {
+    CHARSET_INFO *compatible_cs=
+      get_compatible_charset_with_ctype(args[1]->collation.collation);
+    bool rc= 1;
+    if (compatible_cs)
+    {
+      Item_string *conv_item= new Item_string("", 0, compatible_cs,
+                                              DERIVATION_EXPLICIT);
+      item= args[0];
+      args[0]= conv_item;
+      rc= agg_item_charsets(cmp_collation, func_name(), args, arg_count,
+                            MY_COLL_ALLOW_SUPERSET_CONV |
+                            MY_COLL_ALLOW_COERCIBLE_CONV |
+                            MY_COLL_DISALLOW_NONE, 1);
+      args[0]= item;
+    }
+    else
+      my_error(ER_WRONG_ARGUMENTS, MYF(0), "MATCH");
+    return rc;
+  }
   return agg_arg_collations_for_comparison(cmp_collation,
                                            args+1, arg_count-1, 0);
 }