diff --git a/ts/util/validateConversation.ts b/ts/util/validateConversation.ts
index 6ef677cf64..ecb9791ed0 100644
--- a/ts/util/validateConversation.ts
+++ b/ts/util/validateConversation.ts
@@ -28,7 +28,7 @@ export function validateConversation(
 function validateNumber(attributes: ValidateConversationType): string | null {
   const { e164 } = attributes;
   if (isDirectConversation(attributes) && e164) {
-    if (!/^\+[0-9]{1,19}$/.test(e164)) {
+    if (!/^\+[1-9][0-9]{0,18}$/.test(e164)) {
       return 'Invalid E164';
     }