diff --git a/Gruntfile.js b/Gruntfile.js
index 14077d78..e50595cd 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -40,11 +40,17 @@ module.exports = function(grunt) {
           jasmine = new Jasmine({jasmineCore: jasmineCore});
 
       jasmine.loadConfigFile('./spec/support/jasmine.json');
-      jasmine.onComplete(function(passed) {
-        done(passed);
-      });
 
-      jasmine.execute();
+      jasmine.exitOnCompletion = false;
+      jasmine.execute().then(
+        result => {
+          done(result.overallStatus === 'passed');
+        },
+        err => {
+          console.error(err);
+          exit(1);
+        }
+      );
     }
   );
 
diff --git a/package.json b/package.json
index 84dd9372..093c77fd 100644
--- a/package.json
+++ b/package.json
@@ -44,7 +44,7 @@
     "grunt-contrib-concat": "^1.0.1",
     "grunt-css-url-embed": "^1.11.1",
     "grunt-sass": "^3.0.2",
-    "jasmine": "^3.4.0",
+    "jasmine": "github:jasmine/jasmine-npm#main",
     "jasmine-browser-runner": "github:jasmine/jasmine-browser#main",
     "jsdom": "^15.0.0",
     "load-grunt-tasks": "^4.0.0",
diff --git a/spec/core/integration/EnvSpec.js b/spec/core/integration/EnvSpec.js
index afff7737..a4aaa390 100644
--- a/spec/core/integration/EnvSpec.js
+++ b/spec/core/integration/EnvSpec.js
@@ -465,7 +465,7 @@ describe('Env integration', function() {
 
     var global = {
       setTimeout: function(fn, delay) {
-        setTimeout(fn, delay);
+        return setTimeout(fn, delay);
       },
       clearTimeout: function(fn, delay) {
         clearTimeout(fn, delay);
@@ -1018,7 +1018,7 @@ describe('Env integration', function() {
     var globalSetTimeout = jasmine
         .createSpy('globalSetTimeout')
         .and.callFake(function(cb, t) {
-          setTimeout(cb, t);
+          return setTimeout(cb, t);
         }),
       delayedFunctionForGlobalClock = jasmine.createSpy(
         'delayedFunctionForGlobalClock'
@@ -1033,7 +1033,7 @@ describe('Env integration', function() {
         setTimeout: globalSetTimeout,
         clearTimeout: clearTimeout,
         setImmediate: function(cb) {
-          setTimeout(cb, 0);
+          return setTimeout(cb, 0);
         }
       }
     });
@@ -1108,7 +1108,7 @@ describe('Env integration', function() {
           setInterval: setInterval,
           clearInterval: clearInterval,
           setImmediate: function(cb) {
-            realSetTimeout(cb, 0);
+            return realSetTimeout(cb, 0);
           }
         }
       });
@@ -2258,7 +2258,7 @@ describe('Env integration', function() {
   it('reports errors that occur during loading', function(done) {
     var global = {
       setTimeout: function(fn, delay) {
-        setTimeout(fn, delay);
+        return setTimeout(fn, delay);
       },
       clearTimeout: function(fn, delay) {
         clearTimeout(fn, delay);
@@ -2315,7 +2315,7 @@ describe('Env integration', function() {
       var originalOnerror = jasmine.createSpy('original onerror');
       var global = {
         setTimeout: function(fn, delay) {
-          setTimeout(fn, delay);
+          return setTimeout(fn, delay);
         },
         clearTimeout: function(fn, delay) {
           clearTimeout(fn, delay);
@@ -2516,7 +2516,7 @@ describe('Env integration', function() {
       it('is "failed"', function(done) {
         var global = {
           setTimeout: function(fn, delay) {
-            setTimeout(fn, delay);
+            return setTimeout(fn, delay);
           },
           clearTimeout: function(fn, delay) {
             clearTimeout(fn, delay);
@@ -2774,10 +2774,6 @@ describe('Env integration', function() {
   });
 
   it('provides custom equality testers to async matchers', function(done) {
-    if (jasmine.getEnv().skipBrowserFlake) {
-      jasmine.getEnv().skipBrowserFlake();
-    }
-
     jasmine.getEnv().requirePromises();
 
     var specDone = jasmine.createSpy('specDone');
diff --git a/src/html/_HTMLReporter.scss b/src/html/_HTMLReporter.scss
index d2d58b0d..dc06ff95 100644
--- a/src/html/_HTMLReporter.scss
+++ b/src/html/_HTMLReporter.scss
@@ -1,3 +1,5 @@
+@use "sass:math";
+
 $line-height: 14px;
 $margin-unit: 14px;
 
@@ -117,7 +119,7 @@ body {
 
     li {
       display: inline-block;
-      height: ($line-height / 2) + 3;
+      height: math.div($line-height, 2) + 3;
       width: $line-height;
 
       font-size: 16px;
@@ -132,7 +134,7 @@ body {
       }
 
       &.jasmine-failed {
-        line-height: ($line-height / 2) + 2;
+        line-height: math.div($line-height, 2) + 2;
 
         &:before {
           color: $failing-color;
@@ -284,8 +286,8 @@ body {
       padding-left: 0;
 
       &.jasmine-suite {
-        margin-top: $margin-unit/2;
-        margin-bottom: $margin-unit/2
+        margin-top: math.div($margin-unit, 2);
+        margin-bottom: math.div($margin-unit, 2)
       }
     }