diff --git a/.eslintrc.json b/.eslintrc.json
index 32254892e..22b738a1c 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -7,7 +7,8 @@
     },
     "env": {
         "browser": true,
-        "jasmine": true
+        "jasmine": true,
+        "es6": true
     },
     "plugins": ["lodash"],
     "extends": ["eslint:recommended", "plugin:lodash/canonical"],
diff --git a/package-lock.json b/package-lock.json
index e9e13c024..cd21fd459 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9988,6 +9988,11 @@
 			"dev": true,
 			"optional": true
 		},
+		"filesize": {
+			"version": "4.2.1",
+			"resolved": "https://registry.npmjs.org/filesize/-/filesize-4.2.1.tgz",
+			"integrity": "sha512-bP82Hi8VRZX/TUBKfE24iiUGsB/sfm2WUrwTQyAzQrhO3V9IhcBBNBXMyzLY5orACxRyYJ3d2HeRVX+eFv4lmA=="
+		},
 		"fill-range": {
 			"version": "4.0.0",
 			"resolved": "https://registry.npmjs.org/fill-range/-/fill-range-4.0.0.tgz",
@@ -10299,7 +10304,6 @@
 			"version": "8.1.0",
 			"resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
 			"integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
-			"dev": true,
 			"requires": {
 				"graceful-fs": "^4.2.0",
 				"jsonfile": "^4.0.0",
@@ -10309,8 +10313,7 @@
 				"graceful-fs": {
 					"version": "4.2.3",
 					"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.2.3.tgz",
-					"integrity": "sha512-a30VEBm4PEdx1dRB7MFK7BejejvCvBronbLjht+sHuGYj8PHs7M/5Z+rt5lw551vZ7yfTCj4Vuyy3mSJytDWRQ==",
-					"dev": true
+					"integrity": "sha512-a30VEBm4PEdx1dRB7MFK7BejejvCvBronbLjht+sHuGYj8PHs7M/5Z+rt5lw551vZ7yfTCj4Vuyy3mSJytDWRQ=="
 				}
 			}
 		},
@@ -11535,8 +11538,7 @@
 		"graceful-fs": {
 			"version": "4.1.11",
 			"resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.11.tgz",
-			"integrity": "sha1-Dovf5NHduIVNZOBOp8AOKgJuVlg=",
-			"dev": true
+			"integrity": "sha1-Dovf5NHduIVNZOBOp8AOKgJuVlg="
 		},
 		"handle-thing": {
 			"version": "2.0.0",
@@ -12004,6 +12006,11 @@
 				"minimatch": "^3.0.4"
 			}
 		},
+		"immediate": {
+			"version": "3.0.6",
+			"resolved": "https://registry.npmjs.org/immediate/-/immediate-3.0.6.tgz",
+			"integrity": "sha1-nbHb0Pr43m++D13V5Wu2BigN5ps="
+		},
 		"import-cwd": {
 			"version": "2.1.0",
 			"resolved": "https://registry.npmjs.org/import-cwd/-/import-cwd-2.1.0.tgz",
@@ -12567,6 +12574,11 @@
 			"integrity": "sha1-5kAN8ea1bhMLYcS80JPap/boyhU=",
 			"dev": true
 		},
+		"jed": {
+			"version": "1.1.1",
+			"resolved": "https://registry.npmjs.org/jed/-/jed-1.1.1.tgz",
+			"integrity": "sha1-elSbvZ/+FYWwzQoZHiAwVb7ldLQ="
+		},
 		"jest-worker": {
 			"version": "25.1.0",
 			"resolved": "https://registry.npmjs.org/jest-worker/-/jest-worker-25.1.0.tgz",
@@ -12726,7 +12738,6 @@
 			"version": "4.0.0",
 			"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
 			"integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
-			"dev": true,
 			"requires": {
 				"graceful-fs": "^4.1.6"
 			}
@@ -12963,6 +12974,14 @@
 				"type-check": "~0.3.2"
 			}
 		},
+		"lie": {
+			"version": "3.1.1",
+			"resolved": "https://registry.npmjs.org/lie/-/lie-3.1.1.tgz",
+			"integrity": "sha1-mkNrLMd0bKWd56QfpGmz77dr2H4=",
+			"requires": {
+				"immediate": "~3.0.5"
+			}
+		},
 		"linkify-it": {
 			"version": "2.2.0",
 			"resolved": "https://registry.npmjs.org/linkify-it/-/linkify-it-2.2.0.tgz",
@@ -13025,6 +13044,14 @@
 				"json5": "^0.5.0"
 			}
 		},
+		"localforage": {
+			"version": "1.7.3",
+			"resolved": "https://registry.npmjs.org/localforage/-/localforage-1.7.3.tgz",
+			"integrity": "sha512-1TulyYfc4udS7ECSBT2vwJksWbkwwTX8BzeUIiq8Y07Riy7bDAAnxDaPU/tWyOVmQAcWJIEIFP9lPfBGqVoPgQ==",
+			"requires": {
+				"lie": "3.1.1"
+			}
+		},
 		"locate-path": {
 			"version": "3.0.0",
 			"resolved": "https://registry.npmjs.org/locate-path/-/locate-path-3.0.0.tgz",
@@ -19160,6 +19187,14 @@
 				}
 			}
 		},
+		"pluggable.js": {
+			"version": "2.0.1",
+			"resolved": "https://registry.npmjs.org/pluggable.js/-/pluggable.js-2.0.1.tgz",
+			"integrity": "sha512-SBt6v6Tbp20Jf8hU0cpcc/+HBHGMY8/Q+yA6Ih0tBQE8tfdZ6U4PRG0iNvUUjLx/hVyOP53n0UfGBymlfaaXCg==",
+			"requires": {
+				"lodash": "^4.17.11"
+			}
+		},
 		"po-loader": {
 			"version": "0.5.0",
 			"resolved": "https://registry.npmjs.org/po-loader/-/po-loader-0.5.0.tgz",
@@ -21068,6 +21103,13 @@
 			"integrity": "sha512-Mf37VjirD7RqCVeYgI8jb5K0DymIho/jNJqDgIkMs4cgKbEkvsow8Q6hpvF7Zmys9iEif0oW41hgbeWVZwABJw==",
 			"dev": true
 		},
+		"skeletor.js": {
+			"version": "github:skeletorjs/skeletor#dea2d5791ee894493e30b92662c953efec0e58f6",
+			"from": "github:skeletorjs/skeletor#dea2d5791ee894493e30b92662c953efec0e58f6",
+			"requires": {
+				"lodash": "^4.17.14"
+			}
+		},
 		"slash": {
 			"version": "2.0.0",
 			"resolved": "https://registry.npmjs.org/slash/-/slash-2.0.0.tgz",
@@ -21742,6 +21784,11 @@
 				"through": "^2.3.4"
 			}
 		},
+		"strophe.js": {
+			"version": "1.3.4",
+			"resolved": "https://registry.npmjs.org/strophe.js/-/strophe.js-1.3.4.tgz",
+			"integrity": "sha512-jSLDG8jolhAwGOSgiJ7DTMSYK3wVoEJHKtpVRyEacQZ6CWA6z2WRPJpcFMjsIweq5aP9/XIvKUQqHBu/ZhvESA=="
+		},
 		"style-loader": {
 			"version": "0.23.1",
 			"resolved": "https://registry.npmjs.org/style-loader/-/style-loader-0.23.1.tgz",
@@ -22195,6 +22242,33 @@
 			"integrity": "sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q=",
 			"dev": true
 		},
+		"twemoji": {
+			"version": "12.1.5",
+			"resolved": "https://registry.npmjs.org/twemoji/-/twemoji-12.1.5.tgz",
+			"integrity": "sha512-B0PBVy5xomwb1M/WZxf/IqPZfnoIYy1skXnlHjMwLwTNfZ9ljh8VgWQktAPcJXu8080WoEh6YwQGPVhDVqvrVQ==",
+			"requires": {
+				"fs-extra": "^8.0.1",
+				"jsonfile": "^5.0.0",
+				"twemoji-parser": "12.1.3",
+				"universalify": "^0.1.2"
+			},
+			"dependencies": {
+				"jsonfile": {
+					"version": "5.0.0",
+					"resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-5.0.0.tgz",
+					"integrity": "sha512-NQRZ5CRo74MhMMC3/3r5g2k4fjodJ/wh8MxjFbCViWKFjxrnudWSY5vomh+23ZaXzAS7J3fBZIR2dV6WbmfM0w==",
+					"requires": {
+						"graceful-fs": "^4.1.6",
+						"universalify": "^0.1.2"
+					}
+				}
+			}
+		},
+		"twemoji-parser": {
+			"version": "12.1.3",
+			"resolved": "https://registry.npmjs.org/twemoji-parser/-/twemoji-parser-12.1.3.tgz",
+			"integrity": "sha512-ND4LZXF4X92/PFrzSgGkq6KPPg8swy/U0yRw1k/+izWRVmq1HYi3khPwV3XIB6FRudgVICAaBhJfW8e8G3HC7Q=="
+		},
 		"type-check": {
 			"version": "0.3.2",
 			"resolved": "https://registry.npmjs.org/type-check/-/type-check-0.3.2.tgz",
@@ -22415,8 +22489,7 @@
 		"universalify": {
 			"version": "0.1.2",
 			"resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-			"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
-			"dev": true
+			"integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg=="
 		},
 		"unpipe": {
 			"version": "1.0.0",
diff --git a/src/converse-omemo.js b/src/converse-omemo.js
index 404ee28b4..17c7590a9 100644
--- a/src/converse-omemo.js
+++ b/src/converse-omemo.js
@@ -3,7 +3,7 @@
  * @copyright The Converse.js contributors
  * @license Mozilla Public License (MPLv2)
  */
-/* global libsignal, ArrayBuffer */
+/* global libsignal */
 
 import "converse-profile";
 import { Collection } from "skeletor.js/src/collection";