diff --git a/go/mysql/replication_test.go b/go/mysql/replication_test.go
index c9a54485497..680cb9e68dc 100644
--- a/go/mysql/replication_test.go
+++ b/go/mysql/replication_test.go
@@ -17,6 +17,7 @@ limitations under the License.
 package mysql
 
 import (
+	"math"
 	"reflect"
 	"testing"
 
@@ -37,6 +38,10 @@ func TestComBinlogDump(t *testing.T) {
 		cConn.Close()
 	}()
 
+	// Try to write a ComBinlogDump packet with a position greater than 4 bytes.
+	err := cConn.WriteComBinlogDump(1, "moofarm", math.MaxInt64, 0x0d0e)
+	require.Error(t, err)
+
 	// Write ComBinlogDump packet, read it, compare.
 	if err := cConn.WriteComBinlogDump(0x01020304, "moofarm", 0x05060708, 0x090a); err != nil {
 		t.Fatalf("WriteComBinlogDump failed: %v", err)