diff --git a/apps/btadv/app.js b/apps/btadv/app.js
index ced701d79..67899370e 100644
--- a/apps/btadv/app.js
+++ b/apps/btadv/app.js
@@ -1,4 +1,3 @@
-"use strict";
 var __assign = Object.assign;
 var Layout = require("Layout");
 Bangle.loadWidgets();
diff --git a/apps/clkinfostopw/clkinfo.js b/apps/clkinfostopw/clkinfo.js
index e89c18505..84d7dfecc 100644
--- a/apps/clkinfostopw/clkinfo.js
+++ b/apps/clkinfostopw/clkinfo.js
@@ -1,4 +1,3 @@
-"use strict";
 (function () {
     var durationOnPause = "---";
     var redrawInterval;
diff --git a/apps/clkinfostopw/settings.js b/apps/clkinfostopw/settings.js
index df51cd705..86bf09cdd 100644
--- a/apps/clkinfostopw/settings.js
+++ b/apps/clkinfostopw/settings.js
@@ -1,4 +1,3 @@
-"use strict";
 (function (back) {
     var _a;
     var SETTINGS_FILE = "clkinfostopw.setting.json";
diff --git a/apps/widChargingStatus/widget.js b/apps/widChargingStatus/widget.js
index 46119cc5c..628fac043 100644
--- a/apps/widChargingStatus/widget.js
+++ b/apps/widChargingStatus/widget.js
@@ -1,4 +1,3 @@
-"use strict";
 (function () {
     var icon = require('heatshrink').decompress(atob('ikggMAiEAgYIBmEAg4EB+EAh0AgPggEeCAIEBnwQBAgP+gEP//x///j//8f//k///H//4BYOP/4lBv4bDvwEB4EAvAEBwEAuA7DCAI7BgAQBhEAA'));
     var iconWidth = 18;
diff --git a/apps/widbtstates/widget.js b/apps/widbtstates/widget.js
index 1d32e1bc4..e80da4082 100644
--- a/apps/widbtstates/widget.js
+++ b/apps/widbtstates/widget.js
@@ -1,4 +1,3 @@
-"use strict";
 (function () {
     "ram";
     var _a;
diff --git a/tsconfig.json b/tsconfig.json
index a383f7346..1158f887e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -15,6 +15,7 @@
     "declaration": false,
     "emitDeclarationOnly": false,
     "removeComments": true,
+    "noImplicitUseStrict": true, // disable "use strict"
 
     "newLine": "lf",
     "noEmitHelpers": true, // we link to specific banglejs implementations
@@ -35,7 +36,14 @@
     "noImplicitOverride": true,
     "exactOptionalPropertyTypes": true,
     "useUnknownInCatchVariables": true,
-    "strict": true,
+    //"strict": true, // can't have this with noImplicitUseStrict, instead:
+    "strictNullChecks": true,
+    "strictBindCallApply": true,
+    "strictFunctionTypes": true,
+    "strictPropertyInitialization": true,
+    "noImplicitAny": true,
+    "noImplicitThis": true,
+    "useUnknownInCatchVariables": true,
 
     // simple type checking
     "noUnusedLocals": true,