diff --git a/gulpfile.js b/gulpfile.js
index 7613dca..b5f9a21 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -31,7 +31,7 @@ gulp.task('update_bs_fonts', function(){
     .pipe(gulp.dest('fonts'));
 });
 
-gulp.task('libs', ['update_jquery', 'update_bs_js', 'update_bs_css', 'update_bs_fonts']);
+gulp.task('libs', gulp.series('update_jquery', 'update_bs_js', 'update_bs_css', 'update_bs_fonts'));
 
 gulp.task('scripts', function() {
   return gulp.src(paths.scripts)
@@ -61,4 +61,4 @@ gulp.task('watch', function() {
   gulp.watch(paths.scripts, ['site']);
 });
 
-gulp.task('default', ['scripts'])
+gulp.task('default', gulp.series('scripts'))
diff --git a/package.json b/package.json
index bb1c63c..3376d5d 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,8 @@
     "convert"
   ],
   "scripts": {
-    "test": "./node_modules/mocha/bin/mocha & ./node_modules/qunit/bin/cli.js -t ./test/browser/ExcelFormulaUtilities.test.js -d ./src/core.js -c ./src/ExcelFormulaUtilities.js  & ./node_modules/qunit/bin/cli.js -c ./dist/excel-formula.min.js -t ./test/browser/ExcelFormulaUtilities.test.js & ./node_modules/qunit/bin/cli.js -c ./dist/excel-formula.js -t ./test/browser/ExcelFormulaUtilities.test.js"
+    "build": "gulp",
+    "test": "mocha & qunit -t ./test/browser/ExcelFormulaUtilities.test.js -d ./src/core.js -c ./src/ExcelFormulaUtilities.js  & qunit -c ./dist/excel-formula.min.js -t ./test/browser/ExcelFormulaUtilities.test.js & qunit -c ./dist/excel-formula.js -t ./test/browser/ExcelFormulaUtilities.test.js"
   },
   "main": "index.js",
   "engines": {
@@ -33,13 +34,14 @@
   "devDependencies": {
     "del": "^2.0.2",
     "docco": "~0.6.3",
-    "gulp": "^3.9.0",
+    "fs.extra": "^1.3.2",
+    "gulp": "^4.0.2",
     "gulp-concat": "^2.6.0",
     "gulp-notify": "^2.2.0",
     "gulp-rename": "^1.2.2",
     "gulp-uglify": "^1.4.1",
-    "qunit": "~0.7.7",
-    "fs.extra": "^1.3.2"
+    "mocha": "^9.1.3",
+    "qunit": "~0.7.7"
   },
   "dependencies": {
     "bootstrap": "^4.1.3",