diff --git a/src_features/signMessageEIP712/context.c b/src_features/signMessageEIP712/context.c
index 2c79644..7b45518 100644
--- a/src_features/signMessageEIP712/context.c
+++ b/src_features/signMessageEIP712/context.c
@@ -52,6 +52,10 @@ bool eip712_context_init(void) {
         return false;
     }
 
+    // Since they are optional, they might not be provided by the JSON data
+    explicit_bzero(eip712_context->contract_addr, sizeof(eip712_context->contract_addr));
+    eip712_context->chain_id = 0;
+
     struct_state = NOT_INITIALIZED;
 
     return true;
diff --git a/src_features/signMessageEIP712/context.h b/src_features/signMessageEIP712/context.h
index 5a546fd..d4cc6f5 100644
--- a/src_features/signMessageEIP712/context.h
+++ b/src_features/signMessageEIP712/context.h
@@ -8,6 +8,7 @@
 
 typedef struct {
     uint8_t contract_addr[ADDRESS_LENGTH];
+    uint64_t chain_id;
     uint8_t schema_hash[224 / 8];
 } s_eip712_context;
 
diff --git a/src_features/signMessageEIP712/field_hash.c b/src_features/signMessageEIP712/field_hash.c
index bd079b4..83aa45f 100644
--- a/src_features/signMessageEIP712/field_hash.c
+++ b/src_features/signMessageEIP712/field_hash.c
@@ -181,15 +181,14 @@ static bool field_hash_domain_special_fields(const void *const field_ptr,
         }
         memcpy(eip712_context->contract_addr, data, data_length);
     } else if (strncmp(key, "chainId", keylen) == 0) {
-        uint64_t chainId = u64_from_BE(data, data_length);
-
-        if (chainId != chainConfig->chainId) {
+        eip712_context->chain_id = u64_from_BE(data, data_length);
+        if ((eip712_context->chain_id != 0) && (eip712_context->chain_id != chainConfig->chainId)) {
             apdu_response_code = APDU_RESPONSE_CONDITION_NOT_SATISFIED;
             PRINTF("EIP712Domain chain ID mismatch, expected 0x%.*h, got 0x%.*h !\n",
                    sizeof(chainConfig->chainId),
                    &chainConfig->chainId,
-                   sizeof(chainId),
-                   &chainId);
+                   sizeof(eip712_context->chain_id),
+                   &eip712_context->chain_id);
             return false;
         }
     }
diff --git a/src_features/signMessageEIP712/filtering.c b/src_features/signMessageEIP712/filtering.c
index 7510cd0..7984714 100644
--- a/src_features/signMessageEIP712/filtering.c
+++ b/src_features/signMessageEIP712/filtering.c
@@ -66,7 +66,7 @@ static bool verify_filtering_signature(uint8_t dname_length,
     cx_sha256_init(&hash_ctx);
 
     // Chain ID
-    chain_id = __builtin_bswap64(chainConfig->chainId);
+    chain_id = __builtin_bswap64(eip712_context->chain_id);
     hash_nbytes((uint8_t *) &chain_id, sizeof(chain_id), (cx_hash_t *) &hash_ctx);
 
     // Contract address
diff --git a/tests/ragger/eip712/InputData.py b/tests/ragger/eip712/InputData.py
index 92f84f4..47c3018 100644
--- a/tests/ragger/eip712/InputData.py
+++ b/tests/ragger/eip712/InputData.py
@@ -286,9 +286,16 @@ def prepare_filtering(filtr_data, message):
     else:
         filtering_paths = {}
 
+def handle_optional_domain_values(domain):
+    if "chainId" not in domain.keys():
+        domain["chainId"] = 0
+    if "verifyingContract" not in domain.keys():
+        domain["verifyingContract"] = "0x0000000000000000000000000000000000000000"
+
 def init_signature_context(types, domain):
     global sig_ctx
 
+    handle_optional_domain_values(domain)
     env_key = os.environ["CAL_SIGNATURE_TEST_KEY"]
     key = base64.b64decode(env_key).decode() # base 64 string -> decode bytes -> string
     sig_ctx["key"] = SigningKey.from_pem(key, hashlib.sha256)
diff --git a/tests/ragger/eip712/input_files/12-sign_in-data.json b/tests/ragger/eip712/input_files/12-sign_in-data.json
new file mode 100644
index 0000000..1792e88
--- /dev/null
+++ b/tests/ragger/eip712/input_files/12-sign_in-data.json
@@ -0,0 +1,23 @@
+{
+    "domain": {
+        "name": "Who are You?",
+        "version": "1"
+    },
+    "message": {
+        "banner": "Please sign this message with your wallet",
+        "curDate": 1660659773,
+        "id": 38
+    },
+    "primaryType": "Auth",
+    "types": {
+        "EIP712Domain": [
+            { "name": "name", "type": "string" },
+            { "name": "version", "type": "string" }
+        ],
+        "Auth": [
+            { "name": "banner", "type": "string" },
+            { "name": "curDate", "type": "uint32" },
+            { "name": "id", "type": "uint8" }
+        ]
+    }
+}
diff --git a/tests/ragger/eip712/input_files/12-sign_in-filter.json b/tests/ragger/eip712/input_files/12-sign_in-filter.json
new file mode 100644
index 0000000..69da4f1
--- /dev/null
+++ b/tests/ragger/eip712/input_files/12-sign_in-filter.json
@@ -0,0 +1,7 @@
+{
+    "name": "Ethereum sign-in",
+    "fields": {
+        "curDate": "Timestamp",
+        "id": "Identifier"
+    }
+}
diff --git a/tests/ragger/eip712/input_files/12-sign_in.ini b/tests/ragger/eip712/input_files/12-sign_in.ini
new file mode 100644
index 0000000..83047ab
--- /dev/null
+++ b/tests/ragger/eip712/input_files/12-sign_in.ini
@@ -0,0 +1,4 @@
+[signature]
+v = 1b
+r = 7be1671577753c13bfd1da8b234b6df8484daf47351c2366637fd291dd4aa4d9
+s = 1a7ffbb01dc8a64e9ee97d19b8f154e9eecbe0b1bfb9dcfa781a65e474573963
diff --git a/tests/ragger/test_eip712.py b/tests/ragger/test_eip712.py
index 93bee99..bb53ba8 100644
--- a/tests/ragger/test_eip712.py
+++ b/tests/ragger/test_eip712.py
@@ -75,6 +75,10 @@ def test_eip712_new(app_client: EthereumClient, input_file: Path, verbose: bool,
 
             assert InputData.process_file(app_client, input_file, filter_file) == True
             v, r, s = app_client.eip712_sign_new(bip32)
+            #print("[signature]")
+            #print("v = %s" % (v.hex()))
+            #print("r = %s" % (r.hex()))
+            #print("s = %s" % (s.hex()))
 
             assert v == bytes.fromhex(config["signature"]["v"])
             assert r == bytes.fromhex(config["signature"]["r"])