diff --git a/packages/browser/rollup.config.js b/packages/browser/rollup.config.js
index 5659005ca703..5ff9a761fa38 100644
--- a/packages/browser/rollup.config.js
+++ b/packages/browser/rollup.config.js
@@ -54,6 +54,7 @@ const bundleConfig = {
     format: 'iife',
     name: 'Sentry',
     sourcemap: true,
+    strict: false,
   },
   context: 'window',
   plugins: [
diff --git a/packages/browser/src/tracekit.ts b/packages/browser/src/tracekit.ts
index 2ec6616293f2..a3e5132db1ac 100644
--- a/packages/browser/src/tracekit.ts
+++ b/packages/browser/src/tracekit.ts
@@ -1,6 +1,6 @@
 // tslint:disable
 
-import { getGlobalObject, isError, isErrorEvent } from '@sentry/utils';
+import { getGlobalObject, isError, isErrorEvent, normalize } from '@sentry/utils';
 
 /**
  * @hidden
@@ -274,6 +274,9 @@ TraceKit._report = (function reportModuleWrapper() {
     var err = (e && (e.detail ? e.detail.reason : e.reason)) || e;
     var stack = TraceKit._computeStackTrace(err);
     stack.mechanism = 'onunhandledrejection';
+    if (!stack.message) {
+      stack.message = JSON.stringify(normalize(err))
+    }
     _notifyHandlers(stack, true, err);
   }
 
diff --git a/packages/browser/test/integration/test.js b/packages/browser/test/integration/test.js
index 51416ce9ee85..20a0923fa394 100644
--- a/packages/browser/test/integration/test.js
+++ b/packages/browser/test/integration/test.js
@@ -667,9 +667,9 @@ for (var idx in frames) {
             },
             function(sentryData) {
               if (debounceAssertEventCount(sentryData, 1, done)) {
+                // non-error rejections doesnt provide stacktraces so we can skip the assertion
                 assert.equal(sentryData[0].exception.values[0].value, '"test"');
                 assert.equal(sentryData[0].exception.values[0].type, 'UnhandledRejection');
-                assert.equal(sentryData[0].exception.values[0].stacktrace, undefined);
                 assert.equal(sentryData[0].exception.values[0].mechanism.handled, false);
                 assert.equal(sentryData[0].exception.values[0].mechanism.type, 'onunhandledrejection');
                 done();
@@ -696,9 +696,9 @@ for (var idx in frames) {
             },
             function(sentryData) {
               if (debounceAssertEventCount(sentryData, 1, done)) {
-                assert.isAtMost(sentryData[0].exception.values[0].value.length, 303);
+                // non-error rejections doesnt provide stacktraces so we can skip the assertion
+                assert.equal(sentryData[0].exception.values[0].value.length, 253);
                 assert.equal(sentryData[0].exception.values[0].type, 'UnhandledRejection');
-                assert.equal(sentryData[0].exception.values[0].stacktrace, undefined);
                 assert.equal(sentryData[0].exception.values[0].mechanism.handled, false);
                 assert.equal(sentryData[0].exception.values[0].mechanism.type, 'onunhandledrejection');
                 done();
@@ -725,9 +725,9 @@ for (var idx in frames) {
             },
             function(sentryData) {
               if (debounceAssertEventCount(sentryData, 1, done)) {
+                // non-error rejections doesnt provide stacktraces so we can skip the assertion
                 assert.equal(sentryData[0].exception.values[0].value, '{"a":"b"}');
                 assert.equal(sentryData[0].exception.values[0].type, 'UnhandledRejection');
-                assert.equal(sentryData[0].exception.values[0].stacktrace, undefined);
                 assert.equal(sentryData[0].exception.values[0].mechanism.handled, false);
                 assert.equal(sentryData[0].exception.values[0].mechanism.type, 'onunhandledrejection');
                 done();
@@ -761,9 +761,9 @@ for (var idx in frames) {
             },
             function(sentryData) {
               if (debounceAssertEventCount(sentryData, 1, done)) {
-                assert.isAtMost(sentryData[0].exception.values[0].value.length, 303);
+                // non-error rejections doesnt provide stacktraces so we can skip the assertion
+                assert.equal(sentryData[0].exception.values[0].value.length, 253);
                 assert.equal(sentryData[0].exception.values[0].type, 'UnhandledRejection');
-                assert.equal(sentryData[0].exception.values[0].stacktrace, undefined);
                 assert.equal(sentryData[0].exception.values[0].mechanism.handled, false);
                 assert.equal(sentryData[0].exception.values[0].mechanism.type, 'onunhandledrejection');
                 done();
diff --git a/packages/integrations/rollup.config.js b/packages/integrations/rollup.config.js
index eb75c68ce42c..b6ce941d39fc 100644
--- a/packages/integrations/rollup.config.js
+++ b/packages/integrations/rollup.config.js
@@ -76,6 +76,7 @@ function loadAllIntegrations() {
           file: `build/${file.replace('.ts', build.extension)}`,
           format: 'cjs',
           sourcemap: true,
+          strict: false,
         },
         plugins: build.plugins,
       })),
diff --git a/packages/typescript/tsconfig.json b/packages/typescript/tsconfig.json
index 5ffaa48bcbad..0c848a656746 100644
--- a/packages/typescript/tsconfig.json
+++ b/packages/typescript/tsconfig.json
@@ -1,5 +1,6 @@
 {
   "compilerOptions": {
+    "alwaysStrict": false,
     "declaration": true,
     "declarationMap": true,
     "downlevelIteration": true,
@@ -12,6 +13,7 @@
     "noFallthroughCasesInSwitch": true,
     "noImplicitAny": true,
     "noImplicitReturns": true,
+    "noImplicitUseStrict": true,
     "noImplicitThis": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,