diff --git a/api/client/commands.go b/api/client/commands.go
index 0d11e358f5..6230613fc4 100644
--- a/api/client/commands.go
+++ b/api/client/commands.go
@@ -344,6 +344,7 @@ func (cli *DockerCli) CmdLogin(args ...string) error {
 	if username == "" {
 		promptDefault("Username", authconfig.Username)
 		username = readInput(cli.in, cli.out)
+		username = strings.Trim(username, " ")
 		if username == "" {
 			username = authconfig.Username
 		}