diff --git a/interface/client/lib/ethereum/1_web3js_init.js b/interface/client/lib/ethereum/1_web3js_init.js
index fc80d40a2..15f612e52 100644
--- a/interface/client/lib/ethereum/1_web3js_init.js
+++ b/interface/client/lib/ethereum/1_web3js_init.js
@@ -2,9 +2,15 @@
 if(typeof web3 !== 'undefined') {
   console.info('Web3 already initialized, re-using provider.');
 
-  web3 = new Web3(web3.currentProvider);
+    // add web3 backwards compatibility
+    if(!web3.currentProvider.sendAsync) {
+        web3.currentProvider.sendAsync = web3.currentProvider.send;
+        web3.currentProvider.send = web3.currentProvider.sendSync;
+    }
+
+    web3 = new Web3(web3.currentProvider);
 } else {
-  console.info('Web3 not yet initialized, doing so now with HttpProvider.');
+    console.info('Web3 not yet initialized, doing so now with HttpProvider.');
 
-  web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
+    web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
 }
diff --git a/interface/client/templates/popupWindows/sendTransactionConfirmation.html b/interface/client/templates/popupWindows/sendTransactionConfirmation.html
index 4cc9c5ff8..fc9e25a26 100644
--- a/interface/client/templates/popupWindows/sendTransactionConfirmation.html
+++ b/interface/client/templates/popupWindows/sendTransactionConfirmation.html
@@ -13,7 +13,8 @@ <h1>{{i18n "mist.popupWindows.sendTransactionConfirmation.title.createContract"}
                 {{/if}}
 
                 <div class="container">
-                <div class="transaction-parties">
+                <div class="inner-container">
+                    <div class="transaction-parties">
                     <div>
                         {{#if TemplateVar.get "fromIsContract"}}
                             <i class="overlap-icon icon-doc"></i>
@@ -54,15 +55,35 @@ <h1>{{i18n "mist.popupWindows.sendTransactionConfirmation.title.createContract"}
                 </div>
 
                 {{#if transactionInvalid}}
-                    <p class="info dapp-error"> {{{i18n "mist.popupWindows.sendTransactionConfirmation.estimatedGasError"}}} </p>
+                    <p class="info dapp-error"> 
+                    {{i18n "mist.popupWindows.sendTransactionConfirmation.estimatedGasError"}}
+                    </p>
                 {{else}}
-                    {{#if $and data (TemplateVar.get "toIsContract")}}
-                        <p class="info">{{{i18n "mist.popupWindows.sendTransactionConfirmation.contractExecutionInfo"}}}</p>
-                    {{/if}}
+                    {{#unless $eq (TemplateVar.get "gasError") "notEnoughGas"}}
+                        {{#if $eq (TemplateVar.get "gasError") "overBlockGasLimit"}}
+                            <div class="info dapp-error">
+                                {{i18n "mist.popupWindows.sendTransactionConfirmation.overBlockGasLimit"}}
+                            </div>
+                        {{else}}
+                            {{#if $and data (TemplateVar.get "toIsContract")}}
+                                <p class="info">
+                                {{i18n "mist.popupWindows.sendTransactionConfirmation.contractExecutionInfo"}}
+                                </p>
+                            {{/if}}
+
+                            {{#unless to}}
+                                <p class="info">
+                                {{i18n "mist.popupWindows.sendTransactionConfirmation.contractCreationInfo"}}
+                                </p>
+                            {{/unless}}
 
-                    {{#unless to}}
-                        <p class="info">{{{i18n "mist.popupWindows.sendTransactionConfirmation.contractCreationInfo"}}}</p>
+                        {{/if}}
+                    {{else}}
+                        <div class="info dapp-error not-enough-gas" style="cursor: pointer;">
+                            {{{i18n "mist.popupWindows.sendTransactionConfirmation.notEnoughGas"}}}
+                        </div>
                     {{/unless}}
+
                 {{/if}}
 
                 <div class="fees">
@@ -107,8 +128,8 @@ <h1>{{i18n "mist.popupWindows.sendTransactionConfirmation.title.createContract"}
                 {{#if data}}
                     {{#if showFormattedParams}}
                         <div class="parameters">
-                            <h3>{{{i18n "mist.popupWindows.sendTransactionConfirmation.parameters"}}}
-                                <a href="#" class="toggle-panel">{{{i18n "mist.popupWindows.sendTransactionConfirmation.showRawBytecode"}}}</a>
+                            <h3>{{i18n "mist.popupWindows.sendTransactionConfirmation.parameters"}}
+                                <a href="#" class="toggle-panel">{{i18n "mist.popupWindows.sendTransactionConfirmation.showRawBytecode"}}</a>
                             </h3>
                             <ol>
                             {{# each param in params}}
@@ -121,7 +142,7 @@ <h3>{{{i18n "mist.popupWindows.sendTransactionConfirmation.parameters"}}}
                             <h3>{{i18n "mist.popupWindows.sendTransactionConfirmation.data"}}
 
                             {{# if params}}
-                                <a href="#" class="toggle-panel">{{{i18n "mist.popupWindows.sendTransactionConfirmation.showDecodedParameters"}}}</a>
+                                <a href="#" class="toggle-panel">{{i18n "mist.popupWindows.sendTransactionConfirmation.showDecodedParameters"}}</a>
                             {{else}}
                                 {{#if to}}
                                     {{#unless (TemplateVar.get "lookingUpFunctionSignature")}}
@@ -137,6 +158,7 @@ <h3>{{i18n "mist.popupWindows.sendTransactionConfirmation.data"}}
                     {{/if}}
                 {{/if}}
 
+                </div>
                 </div>
                 <footer>
                 {{#if TemplateVar.get "unlocking"}}
diff --git a/interface/client/templates/popupWindows/sendTransactionConfirmation.js b/interface/client/templates/popupWindows/sendTransactionConfirmation.js
index 52d913731..cad0bbb16 100644
--- a/interface/client/templates/popupWindows/sendTransactionConfirmation.js
+++ b/interface/client/templates/popupWindows/sendTransactionConfirmation.js
@@ -6,12 +6,12 @@ Template Controllers
 
 var setWindowSize = function(template){
     Tracker.afterFlush(function(){
-        ipc.send('backendAction_setWindowSize', 580, template.$('.popup-windows').height() + 120);
+        ipc.send('backendAction_setWindowSize', 580, template.$('.popup-windows .inner-container').height() + 240);
     });
 }
 
 
-var defaultEstimateGas  = 50000000;
+var defaultEstimateGas = 50000000;
 
 /**
 The sendTransaction confirmation popup window template
@@ -89,6 +89,7 @@ var signatureLookupCallback = function(textSignature) {
     }
 };
 
+
 Template['popupWindows_sendTransactionConfirmation'].onCreated(function(){
     var template = this;
 
@@ -97,6 +98,18 @@ Template['popupWindows_sendTransactionConfirmation'].onCreated(function(){
         TemplateVar.set(template, 'params', params);
     });
 
+    // check reactively if provided gas is enough
+    this.autorun(function(){
+        if(TemplateVar.get('estimatedGas') > Number(TemplateVar.get('providedGas')))
+            TemplateVar.set('gasError', 'notEnoughGas');
+        else if(TemplateVar.get('estimatedGas') > 4000000)
+            TemplateVar.set('gasError', 'overBlockGasLimit');
+        else
+            TemplateVar.set('gasError', null);
+    });
+
+
+    // check inital data and gas estimates
     this.autorun(function(){
         TemplateVar.set(template, 'displayDecodedParams', true);
 
@@ -156,23 +169,24 @@ Template['popupWindows_sendTransactionConfirmation'].onCreated(function(){
                 });
             }
 
-            // esitmate gas usage
+            // estimate gas usage
             var estimateData = _.clone(data);
             estimateData.gas = defaultEstimateGas;
             web3.eth.estimateGas(estimateData, function(e, res){
                 console.log('Estimated gas: ', res, e);
                 if(!e && res) {
+
+                        // set the gas to the estimation, if not provided or lower
                     Tracker.nonreactive(function(){
+                        var gas = Number(TemplateVar.get(template, 'providedGas'));
 
-                        if(defaultEstimateGas === res)
+                        if(res === defaultEstimateGas)
                             return TemplateVar.set(template, 'estimatedGas', 'invalid');
-                        else
-                            TemplateVar.set(template, 'estimatedGas', res);
 
-                        // set the gas to the estimation, if not provided or lower
-                        var gas = TemplateVar.get(template, 'providedGas');
+                        TemplateVar.set(template, 'estimatedGas', res);
+
 
-                        if(gas == 0) {
+                        if(!gas && res) {
                             TemplateVar.set(template, 'providedGas', res + 100000);
                             TemplateVar.set(template, 'initialProvidedGas', res + 100000);
                         }
@@ -279,6 +293,16 @@ Template['popupWindows_sendTransactionConfirmation'].events({
         TemplateVar.set('providedGas', gas);
     },
     /**
+    Increase the estimated gas
+
+    @event click .not-enough-gas
+    */
+    'click .not-enough-gas': function(){
+        var gas = Number(TemplateVar.get('estimatedGas')) + 100000;
+        TemplateVar.set('initialProvidedGas', gas);
+        TemplateVar.set('providedGas', gas);
+    },
+    /**
     Cancel the transaction confirmation and close the popup
 
     @event click .cancel
@@ -319,7 +343,7 @@ Template['popupWindows_sendTransactionConfirmation'].events({
         TemplateVar.set('unlocking', true);
 
         // unlock and send transaction!
-        web3.personal.unlockAccountAndSendTransaction(data, pw || '', function(e, res){
+        web3.personal.sendTransaction(data, pw || '', function(e, res){
             pw = null;
             TemplateVar.set(template, 'unlocking', false);
 
diff --git a/interface/i18n/mist.en.i18n.json b/interface/i18n/mist.en.i18n.json
index cf3bd86b7..0ab67c576 100644
--- a/interface/i18n/mist.en.i18n.json
+++ b/interface/i18n/mist.en.i18n.json
@@ -207,8 +207,10 @@
                 "unlocking": "Confirming...",
                 "createContract": "Create contract",
                 "estimatedFee": "Estimated fee consumption",
-                "estimatedGasError": "It seems this transaction will fail. If you submit it, it may consume all the gas you send.",
+                "estimatedGasError": "It seems this transaction will fail. If you submit it, it may consume all the gas you provide.",
                 "transactionThrow": "The contract won't allow this transaction to be executed",
+                "overBlockGasLimit": "The gas required for this execution could exceed the block gas limit.",
+                "notEnoughGas": "Gas might not be enough to successfully finish this transaction.<br>Click here to increase the gas amount.",
                 "noEstimate": "We couldn't estimate the gas.",
                 "gasPrice": "Gas price",
                 "perMillionGas": "ether per million gas",
diff --git a/modules/ipc/methods/eth_sendTransaction.js b/modules/ipc/methods/eth_sendTransaction.js
index d6e4b29b2..60cff2cbb 100644
--- a/modules/ipc/methods/eth_sendTransaction.js
+++ b/modules/ipc/methods/eth_sendTransaction.js
@@ -60,6 +60,8 @@ module.exports = class extends BaseProcessor {
                     width: 580,
                     height: 550,
                     alwaysOnTop: true,
+                    enableLargerThanScreen: false,
+                    resizable: true
                 },
             });
 
diff --git a/package.json b/package.json
index 79880329b..4b46c8ce3 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
     "underscore": "^1.8.3",
     "underscore-deep-extend": "^1.1.5",
     "uuid": "^3.0.1",
-    "web3": "^0.17.0-alpha",
+    "web3": "^0.18.2",
     "yargs": "^6.6.0"
   },
   "devDependencies": {
diff --git a/yarn.lock b/yarn.lock
index f26b1d3fd..f48fa7c5f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4231,13 +4231,14 @@ wdio-dot-reporter@^0.0.6:
   dependencies:
     babel-runtime "^5.8.25"
 
-web3@^0.17.0-alpha:
-  version "0.17.0-beta"
-  resolved "https://registry.yarnpkg.com/web3/-/web3-0.17.0-beta.tgz#57af38245bff7a32099f7ce5780fad5bbc00da5b"
+web3@^0.18.2:
+  version "0.18.2"
+  resolved "https://registry.yarnpkg.com/web3/-/web3-0.18.2.tgz#61b1a6edf5056820e22e1ef082f54c279f4bf758"
   dependencies:
     bignumber.js "git+https://github.com/debris/bignumber.js.git#94d7146671b9719e00a09c29b01a691bc85048c2"
     crypto-js "^3.1.4"
     utf8 "^2.1.1"
+    xhr2 "*"
     xmlhttprequest "*"
 
 webdriverio@^4.0.4:
@@ -4335,6 +4336,10 @@ xdg-basedir@^2.0.0:
   dependencies:
     os-homedir "^1.0.0"
 
+xhr2@*:
+  version "0.1.4"
+  resolved "https://registry.yarnpkg.com/xhr2/-/xhr2-0.1.4.tgz#7f87658847716db5026323812f818cadab387a5f"
+
 xml2js@^0.4.17:
   version "0.4.17"
   resolved "https://registry.yarnpkg.com/xml2js/-/xml2js-0.4.17.tgz#17be93eaae3f3b779359c795b419705a8817e868"