diff --git a/README.md b/README.md
index 1e0ba1b..5618f29 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,16 @@ This extension isn´t available in browser stores yet. Please download from [rel
 
 ## Development
 ### Tools
-This project requires you to install [NPM](https://nodejs.org/en/download/) and [gulp](https://www.npmjs.com/package/gulp).
+This project requires you to install the latestst versions of [Node.js](https://nodejs.org/en/download/), [NPM](https://nodejs.org/en/download/) and [gulp](https://www.npmjs.com/package/gulp).
+Minimum required versions:
+| Tool | Version |
+|-|-|
+| Node.js | => 12.18.x |
+| npm | => 6.14.x |
+| gulp | => 4.0.x |
+| gulp-cli\* | => 2.3.x |
+
+\* only required if you plan to run gulp directly from command line.
 
 ### Build
 ```sh
diff --git a/package-lock.json b/package-lock.json
index 141df3b..c407e8d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3737,19 +3737,35 @@
             "dev": true
         },
         "del": {
-            "version": "5.1.0",
-            "resolved": "https://registry.npmjs.org/del/-/del-5.1.0.tgz",
-            "integrity": "sha512-wH9xOVHnczo9jN2IW68BabcecVPxacIA3g/7z6vhSU/4stOKQzeCRK0yD0A24WiAAUJmmVpWqrERcTxnLo3AnA==",
+            "version": "6.0.0",
+            "resolved": "https://registry.npmjs.org/del/-/del-6.0.0.tgz",
+            "integrity": "sha512-1shh9DQ23L16oXSZKB2JxpL7iMy2E0S9d517ptA1P8iw0alkPtQcrKH7ru31rYtKwF499HkTu+DRzq3TCKDFRQ==",
             "dev": true,
             "requires": {
-                "globby": "^10.0.1",
-                "graceful-fs": "^4.2.2",
+                "globby": "^11.0.1",
+                "graceful-fs": "^4.2.4",
                 "is-glob": "^4.0.1",
                 "is-path-cwd": "^2.2.0",
-                "is-path-inside": "^3.0.1",
-                "p-map": "^3.0.0",
-                "rimraf": "^3.0.0",
+                "is-path-inside": "^3.0.2",
+                "p-map": "^4.0.0",
+                "rimraf": "^3.0.2",
                 "slash": "^3.0.0"
+            },
+            "dependencies": {
+                "globby": {
+                    "version": "11.0.1",
+                    "resolved": "https://registry.npmjs.org/globby/-/globby-11.0.1.tgz",
+                    "integrity": "sha512-iH9RmgwCmUJHi2z5o2l3eTtGBtXek1OYlHrbcxOYugyHLmAsZrPj43OtHThd62Buh/Vv6VyCBD2bdyWcGNQqoQ==",
+                    "dev": true,
+                    "requires": {
+                        "array-union": "^2.1.0",
+                        "dir-glob": "^3.0.1",
+                        "fast-glob": "^3.1.1",
+                        "ignore": "^5.1.4",
+                        "merge2": "^1.3.0",
+                        "slash": "^3.0.0"
+                    }
+                }
             }
         },
         "delayed-stream": {
@@ -5604,15 +5620,14 @@
             }
         },
         "gulp-postcss": {
-            "version": "8.0.0",
-            "resolved": "https://registry.npmjs.org/gulp-postcss/-/gulp-postcss-8.0.0.tgz",
-            "integrity": "sha512-Wtl6vH7a+8IS/fU5W9IbOpcaLqKxd5L1DUOzaPmlnCbX1CrG0aWdwVnC3Spn8th0m8D59YbysV5zPUe1n/GJYg==",
+            "version": "9.0.0",
+            "resolved": "https://registry.npmjs.org/gulp-postcss/-/gulp-postcss-9.0.0.tgz",
+            "integrity": "sha512-5mSQ9CK8salSagrXgrVyILfEMy6I5rUGPRiR9rVjgJV9m/rwdZYUhekMr+XxDlApfc5ZdEJ8gXNZrU/TsgT5dQ==",
             "dev": true,
             "requires": {
-                "fancy-log": "^1.3.2",
+                "fancy-log": "^1.3.3",
                 "plugin-error": "^1.0.1",
-                "postcss": "^7.0.2",
-                "postcss-load-config": "^2.0.0",
+                "postcss-load-config": "^2.1.1",
                 "vinyl-sourcemaps-apply": "^0.2.1"
             }
         },
@@ -8100,9 +8115,9 @@
             }
         },
         "p-map": {
-            "version": "3.0.0",
-            "resolved": "https://registry.npmjs.org/p-map/-/p-map-3.0.0.tgz",
-            "integrity": "sha512-d3qXVTF/s+W+CdJ5A29wywV2n8CQQYahlgz2bFiA+4eVNJbHJodPZ+/gXwPGh0bOqA+j8S+6+ckmvLGPk1QpxQ==",
+            "version": "4.0.0",
+            "resolved": "https://registry.npmjs.org/p-map/-/p-map-4.0.0.tgz",
+            "integrity": "sha512-/bjOqmgETBYB5BoEeGVea8dmvHb2m9GLy1E9W43yeyfP6QQCZGFNa+XRceJEuDB6zqr+gKpIAmlLebMpykw/MQ==",
             "dev": true,
             "requires": {
                 "aggregate-error": "^3.0.0"
@@ -8490,9 +8505,9 @@
             }
         },
         "postcss-load-config": {
-            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/postcss-load-config/-/postcss-load-config-2.1.0.tgz",
-            "integrity": "sha512-4pV3JJVPLd5+RueiVVB+gFOAa7GWc25XQcMp86Zexzke69mKf6Nx9LRcQywdz7yZI9n1udOxmLuAwTBypypF8Q==",
+            "version": "2.1.2",
+            "resolved": "https://registry.npmjs.org/postcss-load-config/-/postcss-load-config-2.1.2.tgz",
+            "integrity": "sha512-/rDeGV6vMUo3mwJZmeHfEDvwnTKKqQ0S7OHUi/kJvvtx3aWtyWG2/0ZWnzCt2keEclwN6Tf0DST2v9kITdOKYw==",
             "dev": true,
             "requires": {
                 "cosmiconfig": "^5.0.0",
diff --git a/package.json b/package.json
index a2dd8be..8859fe1 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
         "browserify": "^16.5.2",
         "cross-env": "^7.0.2",
         "cssnano": "^4.1.10",
-        "del": "^5.1.0",
+        "del": "^6.0.0",
         "gulp": "^4.0.2",
         "gulp-autoprefixer": "^7.0.1",
         "gulp-babel": "^8.0.0",
@@ -53,7 +53,7 @@
         "gulp-imagemin": "^7.1.0",
         "gulp-load-plugins": "^2.0.4",
         "gulp-plumber": "^1.2.1",
-        "gulp-postcss": "^8.0.0",
+        "gulp-postcss": "^9.0.0",
         "gulp-rename": "^2.0.0",
         "gulp-replace": "^1.0.0",
         "gulp-sass": "^4.1.0",