diff --git a/polymesh_schema.json b/polymesh_schema.json
index 4e55e67e41..266d04063f 100644
--- a/polymesh_schema.json
+++ b/polymesh_schema.json
@@ -431,7 +431,7 @@
         "Custom": "Vec<u8>"
       }
     },
-    "InvestorZKProofData": "Signature",
+    "InvestorZKProofData": "[u8; 64]",
     "Scalar": "[u8; 32]",
     "RistrettoPoint": "[u8; 32]",
     "ZkProofData": {