diff --git a/packages/tslint-config/tslint.json b/packages/tslint-config/tslint.json
index 486780de6f..971588b089 100644
--- a/packages/tslint-config/tslint.json
+++ b/packages/tslint-config/tslint.json
@@ -60,6 +60,7 @@
         "prefer-function-over-method": true,
         "promise-function-async": true,
         "quotemark": [true, "single", "avoid-escape", "jsx-double"],
+        "restrict-plus-operands": true,
         "semicolon": [true, "always"],
         "space-before-function-paren": [
             true,
diff --git a/packages/website/ts/components/eth_weth_conversion_button.tsx b/packages/website/ts/components/eth_weth_conversion_button.tsx
index f2c505207c..300e71f1f8 100644
--- a/packages/website/ts/components/eth_weth_conversion_button.tsx
+++ b/packages/website/ts/components/eth_weth_conversion_button.tsx
@@ -105,7 +105,7 @@ export class EthWethConversionButton extends React.Component<
             }
             this.props.onConversionSuccessful();
         } catch (err) {
-            const errMsg = '' + err;
+            const errMsg = `${err}`;
             if (_.includes(errMsg, BlockchainCallErrs.UserHasNoAssociatedAddresses)) {
                 this.props.dispatcher.updateShouldBlockchainErrDialogBeOpen(true);
             } else if (!_.includes(errMsg, 'User denied transaction')) {
diff --git a/packages/website/ts/components/generate_order/generate_order_form.tsx b/packages/website/ts/components/generate_order/generate_order_form.tsx
index 3144fc3bdd..3ae0d48a71 100644
--- a/packages/website/ts/components/generate_order/generate_order_form.tsx
+++ b/packages/website/ts/components/generate_order/generate_order_form.tsx
@@ -329,7 +329,7 @@ export class GenerateOrderForm extends React.Component<GenerateOrderFormProps, G
                                   ${validationResult.errors}`);
             }
         } catch (err) {
-            const errMsg = '' + err;
+            const errMsg = `${err}`;
             if (utils.didUserDenyWeb3Request(errMsg)) {
                 globalErrMsg = 'User denied sign request';
             } else {
diff --git a/packages/website/ts/components/inputs/allowance_toggle.tsx b/packages/website/ts/components/inputs/allowance_toggle.tsx
index 1be441e17b..da46db4f44 100644
--- a/packages/website/ts/components/inputs/allowance_toggle.tsx
+++ b/packages/website/ts/components/inputs/allowance_toggle.tsx
@@ -77,7 +77,7 @@ export class AllowanceToggle extends React.Component<AllowanceToggleProps, Allow
             this.setState({
                 isSpinnerVisible: false,
             });
-            const errMsg = '' + err;
+            const errMsg = `${err}`;
             if (_.includes(errMsg, 'User denied transaction')) {
                 return;
             }
diff --git a/packages/website/ts/components/token_balances.tsx b/packages/website/ts/components/token_balances.tsx
index 112b3fe603..5e7b4e9f60 100644
--- a/packages/website/ts/components/token_balances.tsx
+++ b/packages/website/ts/components/token_balances.tsx
@@ -514,7 +514,7 @@ export class TokenBalances extends React.Component<TokenBalancesProps, TokenBala
             this.props.dispatcher.showFlashMessage(`Successfully minted ${amount.toString(10)} ${token.symbol}`);
             return true;
         } catch (err) {
-            const errMsg = '' + err;
+            const errMsg = `${err}`;
             if (_.includes(errMsg, BlockchainCallErrs.UserHasNoAssociatedAddresses)) {
                 this.props.dispatcher.updateShouldBlockchainErrDialogBeOpen(true);
                 return false;