diff --git a/multisig/michelson/generic.tz b/multisig/michelson/generic.tz
index e521a84..60f5ea9 100644
--- a/multisig/michelson/generic.tz
+++ b/multisig/michelson/generic.tz
@@ -85,6 +85,18 @@ code
           }
           {
             # Change set of signatures
+
+            # Sanity check threshold/key pair
+            DUP;
+            DIP {
+                  UNPAIR;
+
+                  # Check threshold is not zero
+                  DUP; INT; ASSERT_NEQ;
+
+                  # Check threshold less then or equal to number of keys
+                  DIP { SIZE } ; ASSERT_CMPLE; };
+
             DIP { CAR } ; SWAP ; PAIR ; NIL operation
           };
         PAIR }
diff --git a/multisig/michelson/multisig.tz b/multisig/michelson/multisig.tz
index f3ee2a6..e8be2be 100644
--- a/multisig/michelson/multisig.tz
+++ b/multisig/michelson/multisig.tz
@@ -80,5 +80,17 @@ code
                   SET_DELEGATE ; CONS }
                 {
                   # Change set of signatures
+
+                  # Sanity check threshold/key pair
+                  DUP;
+                  DIP {
+                        UNPAIR;
+
+                        # Check threshold is not zero
+                        DUP; INT; ASSERT_NEQ;
+
+                        # Check threshold less then or equal to number of keys
+                        DIP { SIZE } ; ASSERT_CMPLE; };
+
                   DIP { SWAP ; CAR } ; SWAP ; PAIR ; SWAP }} ;
     PAIR }
\ No newline at end of file