diff --git a/tools/traffic/cmd/main.go b/tools/traffic/cmd/main.go
index 473b2a612..62a508629 100644
--- a/tools/traffic/cmd/main.go
+++ b/tools/traffic/cmd/main.go
@@ -40,7 +40,7 @@ func trafficGeneratorMain(ctx *cli.Context) error {
 	var signer core.BlobRequestSigner
 	if config.SignerPrivateKey != "" {
 		log.Println("Using signer private key")
-		signer = auth.NewSigner(config.SignerPrivateKey)
+		signer = auth.NewLocalBlobRequestSigner(config.SignerPrivateKey)
 	}
 
 	generator, err := traffic.NewTrafficGenerator(config, signer)
diff --git a/tools/traffic/flags/flags.go b/tools/traffic/flags/flags.go
index b0fb5834e..aca2eb11a 100644
--- a/tools/traffic/flags/flags.go
+++ b/tools/traffic/flags/flags.go
@@ -74,8 +74,8 @@ var (
 	}
 	SignerPrivateKeyFlag = cli.StringFlag{
 		Name:     common.PrefixFlag(FlagPrefix, "signer-private-key-hex"),
-		Usage:    "Path to the private key file",
-		Required: true,
+		Usage:    "Private key to use for signing requests",
+		Required: false,
 		EnvVar:   common.PrefixEnvVar(envPrefix, "SIGNER_PRIVATE_KEY_HEX"),
 	}
 	CustomQuorumNumbersFlag = cli.IntSliceFlag{