diff --git a/mysql-test/r/func_in.result b/mysql-test/r/func_in.result
index 3cf2afc83d1..f74c63f7260 100644
--- a/mysql-test/r/func_in.result
+++ b/mysql-test/r/func_in.result
@@ -202,3 +202,11 @@ select count(*) from t1 where id not in (1,2);
 count(*)
 1
 drop table t1;
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 SELECT 1 IN (2, NULL);
+SELECT should return NULL.
+SELECT * FROM t1;
+1 IN (2, NULL)
+NULL
+DROP TABLE t1;
+End of 4.1 tests
diff --git a/mysql-test/t/func_in.test b/mysql-test/t/func_in.test
index 2ffe5a2d5f7..ffed2aac2a0 100644
--- a/mysql-test/t/func_in.test
+++ b/mysql-test/t/func_in.test
@@ -109,4 +109,24 @@ select count(*) from t1 where id not in (1);
 select count(*) from t1 where id not in (1,2);
 drop table t1;
 
-# End of 4.1 tests
+
+#
+# BUG#17047: CHAR() and IN() can return NULL without signaling NULL
+# result
+#
+# The problem was in the IN() function that ignored maybe_null flags
+# of all arguments except the first (the one _before_ the IN
+# keyword, '1' in the test case below).
+#
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 SELECT 1 IN (2, NULL);
+--echo SELECT should return NULL.
+SELECT * FROM t1;
+
+DROP TABLE t1;
+
+
+--echo End of 4.1 tests
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 6b6996160a1..859b4e0ecc1 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -1998,7 +1998,6 @@ void Item_func_in::fix_length_and_dec()
     if (cmp_type  == STRING_RESULT)
       in_item->cmp_charset= cmp_collation.collation;
   }
-  maybe_null= args[0]->maybe_null;
   max_length= 1;
 }