diff --git a/commands/ls.go b/commands/ls.go
index 1d3fb0bee8..0f927fcb67 100644
--- a/commands/ls.go
+++ b/commands/ls.go
@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -88,7 +89,7 @@ func parseFilters(filters []string) (FilterOptions, error) {
 	for _, f := range filters {
 		kv := strings.SplitN(f, "=", 2)
 		if len(kv) != 2 {
-			return options, fmt.Errorf("Unsupported filter syntax.")
+			return options, errors.New("Unsupported filter syntax.")
 		}
 		key, value := kv[0], kv[1]