diff --git a/3.restricted-mint-multisig/imports/multisig.leo b/3.restricted-mint-multisig/imports/multisig.leo
index 1652050..2971080 100644
--- a/3.restricted-mint-multisig/imports/multisig.leo
+++ b/3.restricted-mint-multisig/imports/multisig.leo
@@ -5,6 +5,9 @@ program multisig.aleo {
     mapping required_signatures: bool => u64;
     mapping proposals: Proposal => u64;
     mapping signers: address => bool;
+    mapping signed: Signed => bool;
+
+    
 
     struct Proposal {
         program_address: address,
@@ -12,6 +15,11 @@ program multisig.aleo {
         args_hash: field,
     }
 
+    struct Signed {
+        signer: address,
+        proposal: Proposal
+    }
+
     record ticket {
         owner: address,
         program_address: address,
@@ -41,8 +49,14 @@ program multisig.aleo {
 
     finalize sign(caller: address, proposal: Proposal) {
         assert(Mapping::get(signers, caller));
+        Mapping::get(signed, Signed { signer: caller, proposal: proposal });
+
         let signatures: u64 = Mapping::get_or_use(proposals, proposal, 0u64);
+        let isSigned: Signed = Signed{signer: caller, proposal: proposal};
+        assert(!Mapping::get(signed, isSigned));
         Mapping::set(proposals, proposal, signatures + 1u64);
+        Mapping::set(signed, Signed { signer: caller, proposal: proposal }, true);
+
     }
 
     transition add_signer(ticket_: ticket, new_signer: address) {