diff --git a/cmd/flags.go b/cmd/flags.go
index 224e59d..92bbbb9 100644
--- a/cmd/flags.go
+++ b/cmd/flags.go
@@ -109,7 +109,7 @@ var (
 			Name:    "pages-branch",
 			Usage:   "define a branch to fetch assets from",
 			EnvVars: []string{"PAGES_BRANCHES"},
-			Value:   &cli.StringSlice{},
+			Value:   cli.NewStringSlice("pages"),
 		},
 
 		// ############################
diff --git a/cmd/main.go b/cmd/main.go
index d74301d..70cc811 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -63,7 +63,7 @@ func Serve(ctx *cli.Context) error {
 	}
 
 	if len(defaultBranches) == 0 {
-		defaultBranches = []string{"pages"}
+		return fmt.Errorf("no default branches set (PAGES_BRANCHES)")
 	}
 
 	// Init ssl cert database