diff --git a/internal/codespaces/api/api.go b/internal/codespaces/api/api.go
index f509e2661..7f24e490b 100644
--- a/internal/codespaces/api/api.go
+++ b/internal/codespaces/api/api.go
@@ -177,6 +177,7 @@ type CodespaceConnection struct {
 	HostPublicKeys []string `json:"hostPublicKeys"`
 }
 
+// CodespaceFields is the list of exportable fields for a codespace.
 var CodespaceFields = []string{
 	"name",
 	"owner",
diff --git a/pkg/cmd/codespace/ports.go b/pkg/cmd/codespace/ports.go
index eba8e6fc8..19fbb4135 100644
--- a/pkg/cmd/codespace/ports.go
+++ b/pkg/cmd/codespace/ports.go
@@ -158,6 +158,8 @@ func (pi *portInfo) ExportData(fields []string) *map[string]interface{} {
 			data[f] = pi.Label()
 		case "browseUrl":
 			data[f] = pi.BrowseURL()
+		default:
+			panic("unkown field: " + f)
 		}
 	}