diff --git a/expression/integration_test.go b/expression/integration_test.go
index 1e0da39536561..04b4526e3cb53 100644
--- a/expression/integration_test.go
+++ b/expression/integration_test.go
@@ -2180,6 +2180,7 @@ func (s *testIntegrationSuite) TestBuiltin(c *C) {
 	result.Check(testkit.Rows("2017-01-01 00:00:00.00"))
 	result = tk.MustQuery(`select cast(20170118.999 as datetime);`)
 	result.Check(testkit.Rows("2017-01-18 00:00:00"))
+	tk.MustQuery(`select convert(a2.a, unsigned int) from (select cast('"9223372036854775808"' as json) as a) as a2;`)
 
 	tk.MustExec(`create table tb5(a bigint(64) unsigned, b double);`)
 	tk.MustExec(`insert into tb5 (a, b) values (9223372036854776000, 9223372036854776000);`)
diff --git a/types/convert.go b/types/convert.go
index 079a2b0e152ba..4a8368332b5f7 100644
--- a/types/convert.go
+++ b/types/convert.go
@@ -567,7 +567,11 @@ func ConvertJSONToInt(sc *stmtctx.StatementContext, j json.BinaryJSON, unsigned
 		return int64(u), errors.Trace(err)
 	case json.TypeCodeString:
 		str := string(hack.String(j.GetString()))
-		return StrToInt(sc, str)
+		if !unsigned {
+			return StrToInt(sc, str)
+		}
+		u, err := StrToUint(sc, str)
+		return int64(u), errors.Trace(err)
 	}
 	return 0, errors.New("Unknown type code in JSON")
 }
diff --git a/types/convert_test.go b/types/convert_test.go
index 2d5c97cc2a215..de86c398f7195 100644
--- a/types/convert_test.go
+++ b/types/convert_test.go
@@ -721,22 +721,24 @@ func (s *testTypeConvertSuite) TestGetValidInt(c *C) {
 	tests := []struct {
 		origin  string
 		valid   string
+		signed  bool
 		warning bool
 	}{
-		{"100", "100", false},
-		{"-100", "-100", false},
-		{"1abc", "1", true},
-		{"-1-1", "-1", true},
-		{"+1+1", "+1", true},
-		{"123..34", "123", true},
-		{"123.23E-10", "123", true},
-		{"1.1e1.3", "1", true},
-		{"11e1.3", "11", true},
-		{"1.", "1", true},
-		{".1", "0", true},
-		{"", "0", true},
-		{"123e+", "123", true},
-		{"123de", "123", true},
+		{"100", "100", true, false},
+		{"-100", "-100", true, false},
+		{"9223372036854775808", "9223372036854775808", false, false},
+		{"1abc", "1", true, true},
+		{"-1-1", "-1", true, true},
+		{"+1+1", "+1", true, true},
+		{"123..34", "123", true, true},
+		{"123.23E-10", "123", true, true},
+		{"1.1e1.3", "1", true, true},
+		{"11e1.3", "11", true, true},
+		{"1.", "1", true, true},
+		{".1", "0", true, true},
+		{"", "0", true, true},
+		{"123e+", "123", true, true},
+		{"123de", "123", true, true},
 	}
 	sc := new(stmtctx.StatementContext)
 	sc.TruncateAsWarning = true
@@ -746,7 +748,11 @@ func (s *testTypeConvertSuite) TestGetValidInt(c *C) {
 		prefix, err := getValidIntPrefix(sc, tt.origin)
 		c.Assert(err, IsNil)
 		c.Assert(prefix, Equals, tt.valid)
-		_, err = strconv.ParseInt(prefix, 10, 64)
+		if tt.signed {
+			_, err = strconv.ParseInt(prefix, 10, 64)
+		} else {
+			_, err = strconv.ParseUint(prefix, 10, 64)
+		}
 		c.Assert(err, IsNil)
 		warnings := sc.GetWarnings()
 		if tt.warning {