diff --git a/crates/cluster/src/definition.rs b/crates/cluster/src/definition.rs
index ae4e4633..8abf21f5 100644
--- a/crates/cluster/src/definition.rs
+++ b/crates/cluster/src/definition.rs
@@ -556,7 +556,7 @@ impl Definition {
         }
 
         let operator_config_hash_digest = digest_eip712(
-            &get_operator_eip712_type(self.version.as_str()),
+            &get_operator_eip712_type(self.version.as_str())?,
             self,
             &Operator::default(),
         )?;
@@ -1908,6 +1908,18 @@ mod tests {
         assert!(definition.verify_hashes().is_ok());
     }
 
+    #[test]
+    fn cluster_definition_v1_3_0_unsigned_operators() {
+        for fixture in [
+            include_str!("testdata/cluster_definition_v1_3_0_unsigned.json"),
+            include_str!("testdata/cluster_definition_v1_3_0_partial_sigs.json"),
+        ] {
+            let definition = serde_json::from_str::<Definition>(fixture).unwrap();
+
+            assert!(definition.verify_hashes().is_ok());
+        }
+    }
+
     #[test]
     fn cluster_definition_v1_4_0() {
         let json_str = include_str!("testdata/cluster_definition_v1_4_0.json");
diff --git a/crates/cluster/src/eip712sigs.rs b/crates/cluster/src/eip712sigs.rs
index 87ec946a..916d43fe 100644
--- a/crates/cluster/src/eip712sigs.rs
+++ b/crates/cluster/src/eip712sigs.rs
@@ -26,6 +26,10 @@ pub enum EIP712Error {
     /// Failed to sign EIP-712.
     #[error("Failed to sign EIP-712: {0}")]
     FailedToSign(pluto_k1util::K1UtilError),
+
+    /// Definition version does not support EIP-712 signatures.
+    #[error("Version does not support EIP-712 signatures: {0}")]
+    UnsupportedVersion(String),
 }
 
 struct EIP712TypeField {
@@ -116,16 +120,16 @@ fn eip712_terms_and_conditions() -> EIP712Type {
 }
 
 /// Returns the latest or legacy operator eip712 type.
-pub(crate) fn get_operator_eip712_type(version: &str) -> EIP712Type {
+pub(crate) fn get_operator_eip712_type(version: &str) -> Result<EIP712Type> {
     if !Definition::support_eip712_sigs(version) {
-        unreachable!("invalid eip712 signature version"); // This should never happen
+        return Err(EIP712Error::UnsupportedVersion(version.to_string()));
     }
 
     if version == V1_3 {
-        return eip712_v1x3_config_hash();
+        return Ok(eip712_v1x3_config_hash());
     }
 
-    eip712_operator_config_hash()
+    Ok(eip712_operator_config_hash())
 }
 
 /// Returns the digest for the EIP712 structured type for the provided
@@ -240,6 +244,14 @@ mod tests {
         assert_eq!(signature, expected_signature);
     }
 
+    #[test]
+    fn get_operator_eip712_type_rejects_unsupported_version() {
+        assert!(matches!(
+            get_operator_eip712_type(crate::version::V1_2),
+            Err(EIP712Error::UnsupportedVersion(_))
+        ));
+    }
+
     #[test]
     fn enr_digest() {
         let definition = serde_json::from_str::<Definition>(include_str!(
diff --git a/crates/cluster/src/helpers.rs b/crates/cluster/src/helpers.rs
index 28fcdbf5..5f27f02a 100644
--- a/crates/cluster/src/helpers.rs
+++ b/crates/cluster/src/helpers.rs
@@ -178,7 +178,7 @@ pub fn sign_operator(
 ) -> Result<(), crate::eip712sigs::EIP712Error> {
     let config_signature = crate::eip712sigs::sign_eip712(
         secret,
-        &crate::eip712sigs::get_operator_eip712_type(&definition.version),
+        &crate::eip712sigs::get_operator_eip712_type(&definition.version)?,
         definition,
         operator,
     )?;
diff --git a/crates/cluster/src/ssz.rs b/crates/cluster/src/ssz.rs
index 5cf1a448..44126780 100644
--- a/crates/cluster/src/ssz.rs
+++ b/crates/cluster/src/ssz.rs
@@ -323,10 +323,12 @@ pub(crate) fn hash_definition_v1x3or4<H: HashWalker>(
                 put_byte_list(hh, o.enr.as_bytes(), SSZ_MAX_ENR, "enr")?;
 
                 // Field (2) 'ConfigSignature' Bytes65
-                put_bytes_n(hh, &o.config_signature, SSZ_LEN_K1_SIG)?;
+                hh.put_bytes(&o.config_signature)
+                    .map_err(SSZError::<H>::HashWalkerError)?;
 
                 // Field (3) 'ENRSignature' Bytes65
-                put_bytes_n(hh, &o.enr_signature, SSZ_LEN_K1_SIG)?;
+                hh.put_bytes(&o.enr_signature)
+                    .map_err(SSZError::<H>::HashWalkerError)?;
             }
 
             hh.merkleize(op_sub_idx)
diff --git a/crates/cluster/src/testdata/cluster_definition_v1_3_0_partial_sigs.json b/crates/cluster/src/testdata/cluster_definition_v1_3_0_partial_sigs.json
new file mode 100644
index 00000000..877271aa
--- /dev/null
+++ b/crates/cluster/src/testdata/cluster_definition_v1_3_0_partial_sigs.json
@@ -0,0 +1,28 @@
+{
+ "name": "test definition",
+ "operators": [
+  {
+   "address": "0x019192c24224e2cafccae3a61fb586b14323a6bc",
+   "enr": "enr://ea6f5b3af6de0374366c4719e43a1b067d89bc7f01f1f573981659a44ff17a4c",
+   "config_signature": "",
+   "enr_signature": ""
+  },
+  {
+   "address": "0xa6430105220d0b29688b734b8ea0f3ca9936e846",
+   "enr": "enr://f6a63b7f3dfd2567c18979e4d60f26686d9bf2fb26c901ff354cde1607ee294b",
+   "config_signature": "0x39f32b7c7822ba64f84ab43ca0c6e6b91c1fd3be8990434179d3af4491a369012db92d184fc39d1734ff5716428953bb6865fcf92b0c3a17c9028be9914eb7641c",
+   "enr_signature": "0x6c9347800979d1830356f2a54c3deab2a4b4475d63afbe8fb56987c77f5818526f1814be823350eab13935f31d84484517e924aef78ae151c00755925836b7071b"
+  }
+ ],
+ "uuid": "0194FDC2-FA2F-4CC0-81D3-FF12045B73C8",
+ "version": "v1.3.0",
+ "timestamp": "2022-07-19T18:19:58+02:00",
+ "num_validators": 2,
+ "threshold": 3,
+ "fee_recipient_address": "0x52fdfc072182654f163f5f0f9a621d729566c74d",
+ "withdrawal_address": "0x81855ad8681d0d86d1e91e00167939cb6694d2c4",
+ "dkg_algorithm": "default",
+ "fork_version": "0x90000069",
+ "config_hash": "0xc6d3acd4b419aa59ddde2ef268d9fdbf01d68185c7d5151e6d5885058e4a3f26",
+ "definition_hash": "0x52de1a6dad5265cd698a5622b22dd88b7ab2e894554232d28770a9b7aa7ba71d"
+}
\ No newline at end of file
diff --git a/crates/cluster/src/testdata/cluster_definition_v1_3_0_unsigned.json b/crates/cluster/src/testdata/cluster_definition_v1_3_0_unsigned.json
new file mode 100644
index 00000000..a6e17f3d
--- /dev/null
+++ b/crates/cluster/src/testdata/cluster_definition_v1_3_0_unsigned.json
@@ -0,0 +1,28 @@
+{
+ "name": "test definition",
+ "operators": [
+  {
+   "address": "0x019192c24224e2cafccae3a61fb586b14323a6bc",
+   "enr": "enr://ea6f5b3af6de0374366c4719e43a1b067d89bc7f01f1f573981659a44ff17a4c",
+   "config_signature": "",
+   "enr_signature": ""
+  },
+  {
+   "address": "0xa6430105220d0b29688b734b8ea0f3ca9936e846",
+   "enr": "enr://f6a63b7f3dfd2567c18979e4d60f26686d9bf2fb26c901ff354cde1607ee294b",
+   "config_signature": "",
+   "enr_signature": ""
+  }
+ ],
+ "uuid": "0194FDC2-FA2F-4CC0-81D3-FF12045B73C8",
+ "version": "v1.3.0",
+ "timestamp": "2022-07-19T18:19:58+02:00",
+ "num_validators": 2,
+ "threshold": 3,
+ "fee_recipient_address": "0x52fdfc072182654f163f5f0f9a621d729566c74d",
+ "withdrawal_address": "0x81855ad8681d0d86d1e91e00167939cb6694d2c4",
+ "dkg_algorithm": "default",
+ "fork_version": "0x90000069",
+ "config_hash": "0xc6d3acd4b419aa59ddde2ef268d9fdbf01d68185c7d5151e6d5885058e4a3f26",
+ "definition_hash": "0xb6333215f08427104e50f8fba4fa1fa089dc4974b5029f19de84fe85955584e2"
+}
\ No newline at end of file