diff --git a/mysql-test/r/func_str.result b/mysql-test/r/func_str.result
index 92265c77984..d8afbe13c76 100644
--- a/mysql-test/r/func_str.result
+++ b/mysql-test/r/func_str.result
@@ -1992,4 +1992,73 @@ abc
 SELECT INSERT('abc', 6, 3, '1234');
 INSERT('abc', 6, 3, '1234')
 abc
+CREATE TABLE t1 (a INT);
+CREATE VIEW v1 AS SELECT CRC32(a) AS C FROM t1;
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
+SELECT CRC32(a), COUNT(*) FROM t1 GROUP BY 1;
+CRC32(a)	COUNT(*)
+450215437	1
+498629140	1
+1790921346	1
+1842515611	1
+2212294583	1
+2226203566	1
+2366072709	1
+2707236321	1
+4088798008	1
+4194326291	1
+SELECT CRC32(a), COUNT(*) FROM t1 GROUP BY 1 ORDER BY 1;
+CRC32(a)	COUNT(*)
+450215437	1
+498629140	1
+1790921346	1
+1842515611	1
+2212294583	1
+2226203566	1
+2366072709	1
+2707236321	1
+4088798008	1
+4194326291	1
+SELECT * FROM (SELECT CRC32(a) FROM t1) t2;
+CRC32(a)
+2212294583
+450215437
+1842515611
+4088798008
+2226203566
+498629140
+1790921346
+4194326291
+2366072709
+2707236321
+CREATE TABLE t2 SELECT CRC32(a) FROM t1;
+desc t2;
+Field	Type	Null	Key	Default	Extra
+CRC32(a)	int(10) unsigned	YES		NULL	
+SELECT * FROM v1;
+C
+2212294583
+450215437
+1842515611
+4088798008
+2226203566
+498629140
+1790921346
+4194326291
+2366072709
+2707236321
+SELECT * FROM (SELECT * FROM v1) x;
+C
+2212294583
+450215437
+1842515611
+4088798008
+2226203566
+498629140
+1790921346
+4194326291
+2366072709
+2707236321
+DROP TABLE t1, t2;
+DROP VIEW v1;
 End of 5.0 tests
diff --git a/mysql-test/t/func_str.test b/mysql-test/t/func_str.test
index 0e4b404fe3a..bca977e6df3 100644
--- a/mysql-test/t/func_str.test
+++ b/mysql-test/t/func_str.test
@@ -1058,4 +1058,22 @@ SELECT INSERT('abc', 4, 3, '1234');
 SELECT INSERT('abc', 5, 3, '1234');
 SELECT INSERT('abc', 6, 3, '1234');
 
+#
+# Bug #27530: Grouping on crc32, or create table select crc32
+#
+CREATE TABLE t1 (a INT);
+CREATE VIEW v1 AS SELECT CRC32(a) AS C FROM t1;
+
+INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
+SELECT CRC32(a), COUNT(*) FROM t1 GROUP BY 1;
+SELECT CRC32(a), COUNT(*) FROM t1 GROUP BY 1 ORDER BY 1;
+SELECT * FROM (SELECT CRC32(a) FROM t1) t2;
+CREATE TABLE t2 SELECT CRC32(a) FROM t1;
+desc t2;
+SELECT * FROM v1;
+SELECT * FROM (SELECT * FROM v1) x;
+
+DROP TABLE t1, t2;
+DROP VIEW v1;
+
 --echo End of 5.0 tests
diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index 778ea6e9496..d7c4a3eddef 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -790,7 +790,7 @@ class Item_func_crc32 :public Item_int_func
 {
   String value;
 public:
-  Item_func_crc32(Item *a) :Item_int_func(a) {}
+  Item_func_crc32(Item *a) :Item_int_func(a) { unsigned_flag= 1; }
   const char *func_name() const { return "crc32"; }
   void fix_length_and_dec() { max_length=10; }
   longlong val_int();