diff --git a/packages/siwe-parser/lib/abnf.ts b/packages/siwe-parser/lib/abnf.ts
index 8815fe6d..a3238113 100644
--- a/packages/siwe-parser/lib/abnf.ts
+++ b/packages/siwe-parser/lib/abnf.ts
@@ -4,7 +4,7 @@ import { isEIP55Address, parseIntegerNumber } from "./utils";
 
 const GRAMMAR = `
 sign-in-with-ethereum =
-    domain %s" wants you to sign in with your Ethereum account:" LF
+    [ scheme "://" ] domain %s" wants you to sign in with your Ethereum account:" LF
     address LF
     LF
     [ statement LF ]
diff --git a/test/parsing_positive.json b/test/parsing_positive.json
index 05221a55..5e92711e 100644
--- a/test/parsing_positive.json
+++ b/test/parsing_positive.json
@@ -216,5 +216,18 @@
             "nonce": "15050747",
             "issuedAt": "2022-06-30T14:08:51.382Z"
         }
+    },
+    "domain contains optional scheme": {
+        "message": "https://example.com wants you to sign in with your Ethereum account:\n0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2\n\nI accept the ExampleOrg Terms of Service: https://example.com/tos\n\nURI: https://example.com/login\nVersion: 1\nChain ID: 1\nNonce: 32891756\nIssued At: 2021-09-30T16:25:24Z",
+        "fields": {
+            "domain": "example.com",
+            "address": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
+            "statement": "I accept the ExampleOrg Terms of Service: https://example.com/tos",
+            "uri": "https://example.com/login",
+            "version": "1",
+            "chainId": 1,
+            "nonce": "32891756",
+            "issuedAt": "2021-09-30T16:25:24Z"
+        }
     }
 }