diff --git a/ast/functions.go b/ast/functions.go
index 6b0011bbc..6af8c5b50 100755
--- a/ast/functions.go
+++ b/ast/functions.go
@@ -245,6 +245,7 @@ const (
 	Version        = "version"
 	TiDBVersion    = "tidb_version"
 	TiDBIsDDLOwner = "tidb_is_ddl_owner"
+	TiDBDecodePlan = "tidb_decode_plan"
 
 	// control functions
 	If     = "if"
diff --git a/parser_test.go b/parser_test.go
index ea719212f..da4a9b95c 100755
--- a/parser_test.go
+++ b/parser_test.go
@@ -1078,6 +1078,8 @@ func (s *testParserSuite) TestBuiltin(c *C) {
 
 		{`SELECT tidb_version();`, true, "SELECT TIDB_VERSION()"},
 		{`SELECT tidb_is_ddl_owner();`, true, "SELECT TIDB_IS_DDL_OWNER()"},
+		{`SELECT tidb_decode_plan();`, true, "SELECT TIDB_DECODE_PLAN()"},
+		{`SELECT tidb_decode_key('abc');`, true, "SELECT TIDB_DECODE_KEY('abc')"},
 
 		// for time fsp
 		{"CREATE TABLE t( c1 TIME(2), c2 DATETIME(2), c3 TIMESTAMP(2) );", true, "CREATE TABLE `t` (`c1` TIME(2),`c2` DATETIME(2),`c3` TIMESTAMP(2))"},