diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index 320bb89b62e..ec6032be882 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -847,3 +847,11 @@ num	(select num + 2 FROM t1 LIMIT 1)
 SELECT a.a + 1 AS num FROM t1 a JOIN t1 b ON num = b.a;
 ERROR 42S22: Unknown column 'num' in 'on clause'
 DROP TABLE t1;
+CREATE TABLE t1 (a int);
+SELECT p.a AS val, q.a AS val1 FROM t1 p, t1 q ORDER BY val > 1;
+val	val1
+SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val;
+ERROR 23000: Column 'val' in order clause is ambiguous
+SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val > 1;
+ERROR 23000: Column 'val' in order clause is ambiguous
+DROP TABLE t1;
diff --git a/mysql-test/t/order_by.test b/mysql-test/t/order_by.test
index a8024be7032..3c23ea76d99 100644
--- a/mysql-test/t/order_by.test
+++ b/mysql-test/t/order_by.test
@@ -575,4 +575,19 @@ SELECT a + 1 AS num, (select num + 2 FROM t1 LIMIT 1) FROM t1;
 SELECT a.a + 1 AS num FROM t1 a JOIN t1 b ON num = b.a;
 DROP TABLE t1;
 
+#
+# Bug #25427: crash when order by expression contains a name
+#             that cannot be resolved unambiguously               
+#
+
+CREATE TABLE t1 (a int);
+
+SELECT p.a AS val, q.a AS val1 FROM t1 p, t1 q ORDER BY val > 1;
+--error 1052
+SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val;
+--error 1052
+SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val > 1;
+
+DROP TABLE t1;
+
 # End of 4.1 tests
diff --git a/sql/item.cc b/sql/item.cc
index 45d7856b2c1..1e8c70c6616 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -1761,6 +1761,8 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
         Item** res= find_item_in_list(this, thd->lex->current_select->item_list,
                                       &counter, REPORT_EXCEPT_NOT_FOUND,
                                       &not_used);
+        if (!res)
+          return 1;
         if (res != (Item **)not_found_item)
         {
           if ((*res)->type() == Item::FIELD_ITEM)