diff --git a/js/src/modals/ExecuteContract/executeContract.js b/js/src/modals/ExecuteContract/executeContract.js
index afcc826b7..74f36df34 100644
--- a/js/src/modals/ExecuteContract/executeContract.js
+++ b/js/src/modals/ExecuteContract/executeContract.js
@@ -25,6 +25,7 @@ import ContentClear from 'material-ui/svg-icons/content/clear';
 import NavigationArrowBack from 'material-ui/svg-icons/navigation/arrow-back';
 import NavigationArrowForward from 'material-ui/svg-icons/navigation/arrow-forward';
 
+import { toWei } from '~/api/util/wei';
 import { BusyStep, Button, CompletedStep, GasPriceEditor, IdentityIcon, Modal, TxHash } from '~/ui';
 import { MAX_GAS_ESTIMATION } from '~/util/constants';
 import { validateAddress, validateUint } from '~/util/validation';
@@ -56,12 +57,12 @@ class ExecuteContract extends Component {
   }
 
   static propTypes = {
-    isTest: PropTypes.bool,
-    fromAddress: PropTypes.string,
     accounts: PropTypes.object,
     balances: PropTypes.object,
-    contract: PropTypes.object,
+    contract: PropTypes.object.isRequired,
+    fromAddress: PropTypes.string,
     gasLimit: PropTypes.object.isRequired,
+    isTest: PropTypes.bool,
     onClose: PropTypes.func.isRequired,
     onFromAddressChange: PropTypes.func.isRequired
   }
@@ -77,11 +78,11 @@ class ExecuteContract extends Component {
     funcError: null,
     gasEdit: false,
     rejected: false,
-    step: STEP_DETAILS,
     sending: false,
+    step: STEP_DETAILS,
+    txhash: null,
     values: [],
-    valuesError: [],
-    txhash: null
+    valuesError: []
   }
 
   componentDidMount () {
@@ -255,10 +256,6 @@ class ExecuteContract extends Component {
         valueError = validateAddress(_value).addressError;
         break;
 
-      case 'bool':
-        value = _value === 'true';
-        break;
-
       case 'uint':
         valueError = validateUint(_value).valueError;
         break;
@@ -278,13 +275,12 @@ class ExecuteContract extends Component {
   }
 
   estimateGas = (_fromAddress) => {
-    const { api } = this.context;
     const { fromAddress } = this.props;
     const { amount, func, values } = this.state;
     const options = {
       gas: MAX_GAS_ESTIMATION,
       from: _fromAddress || fromAddress,
-      value: api.util.toWei(amount || 0)
+      value: toWei(amount || 0)
     };
 
     if (!func) {
diff --git a/js/src/modals/ExecuteContract/executeContract.spec.js b/js/src/modals/ExecuteContract/executeContract.spec.js
new file mode 100644
index 000000000..6a8cc692d
--- /dev/null
+++ b/js/src/modals/ExecuteContract/executeContract.spec.js
@@ -0,0 +1,69 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import { shallow } from 'enzyme';
+import React from 'react';
+import sinon from 'sinon';
+
+import ExecuteContract from './';
+
+import { CONTRACT, STORE } from './executeContract.test.js';
+
+let component;
+let onClose;
+let onFromAddressChange;
+
+function render (props) {
+  onClose = sinon.stub();
+  onFromAddressChange = sinon.stub();
+
+  component = shallow(
+    <ExecuteContract
+      { ...props }
+      contract={ CONTRACT }
+      onClose={ onClose }
+      onFromAddressChange={ onFromAddressChange } />,
+      { context: { api: {}, store: STORE } }
+  ).find('ExecuteContract').shallow();
+
+  return component;
+}
+
+describe('modals/ExecuteContract/DetailsStep', () => {
+  it('renders', () => {
+    expect(render({ accounts: {} })).to.be.ok;
+  });
+
+  describe('instance functions', () => {
+    beforeEach(() => {
+      render({
+        accounts: {}
+      });
+    });
+
+    describe('onValueChange', () => {
+      it('toggles boolean from false to true', () => {
+        component.setState({
+          func: CONTRACT.functions[0],
+          values: [false]
+        });
+        component.instance().onValueChange(null, 0, true);
+
+        expect(component.state().values).to.deep.equal([true]);
+      });
+    });
+  });
+});
diff --git a/js/src/modals/ExecuteContract/executeContract.test.js b/js/src/modals/ExecuteContract/executeContract.test.js
new file mode 100644
index 000000000..212aba2c8
--- /dev/null
+++ b/js/src/modals/ExecuteContract/executeContract.test.js
@@ -0,0 +1,64 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import BigNumber from 'bignumber.js';
+import sinon from 'sinon';
+
+const CONTRACT = {
+  functions: [
+    {
+      name: 'test_a',
+      signature: 'test_a',
+      estimateGas: sinon.stub().resolves(new BigNumber(123)),
+      inputs: [
+        {
+          name: 'test_bool',
+          kind: {
+            type: 'bool'
+          }
+        }
+      ],
+      abi: {
+        inputs: [
+          {
+            name: 'test_bool',
+            type: 'bool'
+          }
+        ]
+      }
+    }
+  ]
+};
+
+const STORE = {
+  dispatch: sinon.stub(),
+  subscribe: sinon.stub(),
+  getState: () => {
+    return {
+      balances: {
+        balances: {}
+      },
+      nodeStatus: {
+        gasLimit: new BigNumber(123)
+      }
+    };
+  }
+};
+
+export {
+  CONTRACT,
+  STORE
+};