diff --git a/cmd/utilities/generate_signing_key/main.go b/cmd/utilities/generate_signing_key/main.go
index 90d3c979..4935a8c7 100644
--- a/cmd/utilities/generate_signing_key/main.go
+++ b/cmd/utilities/generate_signing_key/main.go
@@ -43,16 +43,16 @@ func main() {
 	switch *outputFormat {
 	case "synapse":
 		b, err = synapse.EncodeSigningKey(keyVersion, priv)
-		break
 	case "dendrite":
 		b, err = dendrite.EncodeSigningKey(keyVersion, priv)
-		break
 	case "mmr":
 		b, err = mmr.EncodeSigningKey(keyVersion, priv)
-		break
 	default:
 		logrus.Fatalf("Unknown output format '%s'. Try '%s -help' for information.", *outputFormat, flag.Arg(0))
 	}
+	if err != nil {
+		logrus.Fatal(err)
+	}
 
 	f, err := os.Create(*outputFile)
 	if err != nil {