diff --git a/3.restricted-mint-multisig/imports/multisig.leo b/3.restricted-mint-multisig/imports/multisig.leo
index 1652050..a63a618 100644
--- a/3.restricted-mint-multisig/imports/multisig.leo
+++ b/3.restricted-mint-multisig/imports/multisig.leo
@@ -5,6 +5,12 @@ program multisig.aleo {
     mapping required_signatures: bool => u64;
     mapping proposals: Proposal => u64;
     mapping signers: address => bool;
+    mapping VerifySig: Sign => bool;
+
+    struct Sign {
+        proposal: Proposal,
+        signer_address: address
+    }
 
     struct Proposal {
         program_address: address,
@@ -41,6 +47,15 @@ program multisig.aleo {
 
     finalize sign(caller: address, proposal: Proposal) {
         assert(Mapping::get(signers, caller));
+        
+        let propA: Sign = Sign {
+            proposal: proposal,
+            signer_address: caller
+        };
+
+        assert(!Mapping::get_ur_use(VerifySig, propA,false));
+        Mapping::set(VerifySig, propA, true);
+
         let signatures: u64 = Mapping::get_or_use(proposals, proposal, 0u64);
         Mapping::set(proposals, proposal, signatures + 1u64);
     }