diff --git a/aipcli/dial.go b/aipcli/dial.go
index e9a3cc7..3098e0d 100644
--- a/aipcli/dial.go
+++ b/aipcli/dial.go
@@ -48,37 +48,7 @@ func dial(cmd *cobra.Command) (*grpc.ClientConn, error) {
 		)
 	}
 	if isForceTrace(cmd) {
-		traceID, err := generateTraceID()
-		if err != nil {
-			return nil, fmt.Errorf("failed to generate trace ID: %w", err)
-		}
-		spanID, err := generateSpanID()
-		if err != nil {
-			return nil, fmt.Errorf("failed to generate span ID: %w", err)
-		}
-		opts = append(
-			opts,
-			grpc.WithUnaryInterceptor(func(
-				ctx context.Context,
-				method string,
-				req interface{},
-				reply interface{},
-				cc *grpc.ClientConn,
-				invoker grpc.UnaryInvoker,
-				opts ...grpc.CallOption,
-			) error {
-				// See https://cloud.google.com/trace/docs/setup#force-trace
-				const header = "x-cloud-trace-context"
-				value := fmt.Sprintf("%s/%d;o=1", traceID, spanID)
-				cmd.PrintErrln(">> trace ID:", traceID)
-				if IsVerbose(cmd) {
-					cmd.PrintErrln(">> span ID:", spanID)
-					cmd.PrintErrln(">> trace header:", header, "=", value)
-				}
-				ctx = metadata.AppendToOutgoingContext(ctx, header, value)
-				return invoker(ctx, method, req, reply, cc, opts...)
-			}),
-		)
+		opts = append(opts, withForceTrace(cmd))
 	}
 	systemCertPool, err := x509.SystemCertPool()
 	if err != nil {
@@ -101,6 +71,9 @@ func dialInsecure(cmd *cobra.Command) (*grpc.ClientConn, error) {
 	if token != "" {
 		opts = append(opts, grpc.WithPerRPCCredentials(insecureTokenCredentials(token)))
 	}
+	if isForceTrace(cmd) {
+		opts = append(opts, withForceTrace(cmd))
+	}
 	return grpc.NewClient(withDefaultPort(address, 443), opts...)
 }
 
@@ -130,18 +103,39 @@ func withDefaultPort(target string, port int) string {
 	return target
 }
 
-func generateTraceID() (string, error) {
+func withForceTrace(cmd *cobra.Command) grpc.DialOption {
+	traceID := generateTraceID()
+	spanID := generateSpanID()
+	return grpc.WithUnaryInterceptor(func(
+		ctx context.Context,
+		method string,
+		req interface{},
+		reply interface{},
+		cc *grpc.ClientConn,
+		invoker grpc.UnaryInvoker,
+		opts ...grpc.CallOption,
+	) error {
+		// See https://cloud.google.com/trace/docs/setup#force-trace
+		const header = "x-cloud-trace-context"
+		value := fmt.Sprintf("%s/%d;o=1", traceID, spanID)
+		cmd.PrintErrln(">> trace ID:", traceID)
+		if IsVerbose(cmd) {
+			cmd.PrintErrln(">> span ID:", spanID)
+			cmd.PrintErrln(">> trace header:", header, "=", value)
+		}
+		ctx = metadata.AppendToOutgoingContext(ctx, header, value)
+		return invoker(ctx, method, req, reply, cc, opts...)
+	})
+}
+
+func generateTraceID() string {
 	var id [16]byte
-	if _, err := rand.Read(id[:]); err != nil {
-		return "", err
-	}
-	return hex.EncodeToString(id[:]), nil
+	_, _ = rand.Read(id[:]) // panics on error
+	return hex.EncodeToString(id[:])
 }
 
-func generateSpanID() (uint64, error) {
+func generateSpanID() uint64 {
 	var id [8]byte
-	if _, err := rand.Read(id[:]); err != nil {
-		return 0, err
-	}
-	return binary.LittleEndian.Uint64(id[:]), nil
+	_, _ = rand.Read(id[:]) // panics on error
+	return binary.LittleEndian.Uint64(id[:])
 }