diff --git a/lib/address.js b/lib/address.js
index 2fd487e9d..b017bc7f4 100644
--- a/lib/address.js
+++ b/lib/address.js
@@ -195,14 +195,10 @@ Address._transformBuffer = function(buffer, network, type) {
     throw new TypeError('Address buffers must be exactly 21 bytes.');
   }
 
-  var networkObj = Networks.get(network);
+  network = Networks.get(network);
   var bufferVersion = Address._classifyFromVersion(buffer);
 
-  if (network && !networkObj) {
-    throw new TypeError('Unknown network');
-  }
-
-  if (!bufferVersion.network || (networkObj && networkObj !== bufferVersion.network)) {
+  if (!bufferVersion.network || (network && network !== bufferVersion.network)) {
     throw new TypeError('Address has mismatched network type.');
   }
 
diff --git a/lib/transaction/transaction.js b/lib/transaction/transaction.js
index 947af4336..9be4e4974 100644
--- a/lib/transaction/transaction.js
+++ b/lib/transaction/transaction.js
@@ -393,13 +393,13 @@ Transaction.prototype.fromObject = function fromObject(arg) {
 
 Transaction.prototype._checkConsistency = function(arg) {
   if (!_.isUndefined(this._changeIndex)) {
-    $.checkState(this._changeScript, 'Change script is expected.');
-    $.checkState(this.outputs[this._changeIndex], 'Change index points to undefined output.');
+    $.checkState(this._changeScript);
+    $.checkState(this.outputs[this._changeIndex]);
     $.checkState(this.outputs[this._changeIndex].script.toString() ===
-      this._changeScript.toString(), 'Change output has an unexpected script.');
+      this._changeScript.toString());
   }
   if (arg && arg.hash) {
-    $.checkState(arg.hash === this.hash, 'Hash in object does not match transaction hash.');
+    $.checkState(arg.hash === this.hash, 'Hash in object does not match transaction hash');
   }
 };
 
@@ -1050,7 +1050,7 @@ Transaction.prototype.removeInput = function(txId, outputIndex) {
  * @return {Transaction} this, for chaining
  */
 Transaction.prototype.sign = function(privateKey, sigtype) {
-  $.checkState(this.hasAllUtxoInfo(), 'Not all utxo information is available to sign the transaction.');
+  $.checkState(this.hasAllUtxoInfo());
   var self = this;
   if (_.isArray(privateKey)) {
     _.each(privateKey, function(privateKey) {
diff --git a/test/address.js b/test/address.js
index f4632c713..4982ad701 100644
--- a/test/address.js
+++ b/test/address.js
@@ -250,12 +250,6 @@ describe('Address', function() {
       Address.fromString(str, Networks.livenet).toString().should.equal(str);
     });
 
-    it('should throw with bad network param', function() {
-      (function(){
-        Address.fromString(str, 'somenet');
-      }).should.throw('Unknown network');
-    });
-
     it('should error because of unrecognized data format', function() {
       (function() {
         return new Address(new Error());
diff --git a/test/networks.js b/test/networks.js
index ea265cf9d..7d82f927f 100644
--- a/test/networks.js
+++ b/test/networks.js
@@ -89,10 +89,7 @@ describe('Networks', function() {
     networks.add(custom);
     var network = networks.get(undefined);
     should.not.exist(network);
-    var somenet = networks.get('somenet');
-    should.exist(somenet);
-    somenet.name.should.equal('somenet');
-    networks.remove(somenet);
+    networks.remove(custom);
   });
 
   var constants = ['name', 'alias', 'pubkeyhash', 'scripthash', 'xpubkey', 'xprivkey'];