diff --git a/command/exec.go b/command/exec.go
index c623002..e5744d1 100644
--- a/command/exec.go
+++ b/command/exec.go
@@ -369,6 +369,9 @@ func registerExec(app *kingpin.Application) {
 			),
 		).BoolVar(&c.Pretty)
 
+	cmd.Flag("max-procs", "limits the number of concurrent steps the runner can execute simultaneously").
+		Int64Var(&c.Procs)
+
 	// shared pipeline flags
 	c.Flags = internal.ParseFlags(cmd)
 }