diff --git a/js/coin.js b/js/coin.js
index 6f77b2c..84362e5 100644
--- a/js/coin.js
+++ b/js/coin.js
@@ -132,7 +132,13 @@
 		var checksum = r.slice(0,4);
 		var redeemScript = Crypto.util.bytesToHex(s.buffer);
 		var address = coinjs.base58encode(x.concat(checksum));
-		return {'address':address, 'redeemScript':redeemScript};
+
+		if(s.buffer.length > 520){ // too large
+			address = 'invalid';
+			redeemScript = 'invalid';
+		}
+
+		return {'address':address, 'redeemScript':redeemScript, 'size': s.buffer.length};
 	}
 
 	/* new time locked address, provide the pubkey and time necessary to unlock the funds.
diff --git a/js/coinbin.js b/js/coinbin.js
index 2d1c180..c07170a 100644
--- a/js/coinbin.js
+++ b/js/coinbin.js
@@ -379,11 +379,15 @@ $(document).ready(function() {
 		if(($("#multisigPubKeys .pubkey").parent().hasClass('has-error')==false) && $("#releaseCoins").parent().hasClass('has-error')==false){
 			var sigsNeeded = $("#releaseCoins option:selected").html();
 			var multisig =  coinjs.pubkeys2MultisigAddress(keys, sigsNeeded);
-			$("#multiSigData .address").val(multisig['address']);
-			$("#multiSigData .script").val(multisig['redeemScript']);
-			$("#multiSigData .scriptUrl").val(document.location.origin+''+document.location.pathname+'?verify='+multisig['redeemScript']+'#verify');
-			$("#multiSigData").removeClass('hidden').addClass('show').fadeIn();
-			$("#releaseCoins").removeClass('has-error');
+			if(multisig.size <= 520){
+				$("#multiSigData .address").val(multisig['address']);
+				$("#multiSigData .script").val(multisig['redeemScript']);
+				$("#multiSigData .scriptUrl").val(document.location.origin+''+document.location.pathname+'?verify='+multisig['redeemScript']+'#verify');
+				$("#multiSigData").removeClass('hidden').addClass('show').fadeIn();
+				$("#releaseCoins").removeClass('has-error');
+			} else {
+				$("#multiSigErrorMsg").html('<span class="glyphicon glyphicon-exclamation-sign"></span> Your generated redeemscript is too large (>520 bytes) it can not be used safely').fadeIn();
+			}
 		} else {
 			$("#multiSigErrorMsg").html('<span class="glyphicon glyphicon-exclamation-sign"></span> One or more public key is invalid!').fadeIn();
 		}
diff --git a/sha1sum b/sha1sum
index 3837299..ae427ac 100644
--- a/sha1sum
+++ b/sha1sum
@@ -1,9 +1,9 @@
----- Version 1.3 2017.10.01 ----
+---- Version 1.3 2017.10.04 ----
 77e4519962e2f6a9fc93342137dbb31c33b76b04  ./js/aes.js
 3a09a8fc0cfe828b57fc798d668234d0490ee1a6  ./js/bootstrap-datetimepicker.min.js
 253711c6d825de55a8360552573be950da180614  ./js/bootstrap.min.js
-e25332acfd75cb76139a5f9ebe268fa7374e8989  ./js/coinbin.js
-494cefb8d6e59415ad25587de87a3dd1c055855e  ./js/coin.js
+8e9b7114276b56d1073698f025f707523d53631b  ./js/coinbin.js
+31fbebf65d9cae8f26761cb057c4fb1b97339d08  ./js/coin.js
 988565bc2cb402d63ed5c5fd7ff47c4278efc2c5  ./js/collapse.js
 9ba5ede3d7f9d4c8fd623395f196adfdcf7e970f  ./js/crypto-min.js
 f7c09f2f5a721371e7d478050119f7e2d58e3ef9  ./js/crypto-sha256-hmac.js