diff --git a/cmd/tinyauth/create_oidc_client.go b/cmd/tinyauth/create_oidc_client.go
index 9efb154..989d41b 100644
--- a/cmd/tinyauth/create_oidc_client.go
+++ b/cmd/tinyauth/create_oidc_client.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/google/uuid"
 	"github.com/steveiliop56/tinyauth/internal/utils"
@@ -25,6 +26,11 @@ func createOidcClientCmd() *cli.Command {
 
 			clientName := args[0]
 
+			// prevent client name from using periods or underscores in order to prevent breaking flags or env vars
+			if strings.Contains(clientName, "_") || strings.Contains(clientName, ".") {
+				tlog.App.Fatal().Msg("Client name cannot contain underscores or periods")
+			}
+
 			uuid := uuid.New()
 			clientId := uuid.String()
 			clientSecret := "ta-" + utils.GenerateString(61)