diff --git a/.jscsrc b/.jscsrc
deleted file mode 100644
index 9dd5ab82e6..0000000000
--- a/.jscsrc
+++ /dev/null
@@ -1,78 +0,0 @@
-
-{
-  "excludeFiles": ["node_modules/**", "**/build/**"],
-  "requireCurlyBraces": [
-    "if", "else", "for", "while", "do", "try", "catch"
-  ],
-  "requireSpaceBeforeKeywords": [
-    "else", "while", "catch"
-  ],
-  "requireSpaceAfterKeywords": [
-    "do", "for", "if", "else", "switch", "case", "try", "catch", "while", "return", "typeof"
-  ],
-  "requireSpaceBeforeBlockStatements": true,
-  "requireParenthesesAroundIIFE": true,
-  "requireSpacesInConditionalExpression": {
-    "afterTest": true,
-    "beforeConsequent": true,
-    "afterConsequent": true,
-    "beforeAlternate": true
-  },
-  "requireSpacesInAnonymousFunctionExpression": {
-    "beforeOpeningCurlyBrace": true
-  },
-  "disallowSpacesInNamedFunctionExpression": {
-    "beforeOpeningRoundBrace": true
-  },
-  "requireSpacesInFunction": {
-    "beforeOpeningCurlyBrace": true
-  },
-  "disallowSpacesInCallExpression": true,
-  "requireBlocksOnNewline": true,
-  "requirePaddingNewlinesBeforeKeywords": ["case"],
-  "disallowEmptyBlocks": true,
-  "disallowSpacesInsideArrayBrackets": "nested",
-  "disallowSpacesInsideParentheses": true,
-  "requireSpacesInsideObjectBrackets": "all",
-  "disallowQuotedKeysInObjects": "allButReserved",
-  "disallowSpaceAfterObjectKeys": true,
-  "requireSpaceBeforeObjectValues": true,
-  "requireCommaBeforeLineBreak": true,
-  "requireOperatorBeforeLineBreak": [
-    "?", "=", "+", "-", "/", "*", "===", "!==", ">", ">=", "<", "<="
-  ],
-  "disallowSpaceAfterPrefixUnaryOperators": ["++", "--", "+", "-", "~", "!"],
-  "disallowSpaceBeforePostfixUnaryOperators": ["++", "--"],
-  "requireSpaceBeforeBinaryOperators": [
-    "=", "+", "+=", "-", "-=", "/", "/=", "*", "*=", "===", "!==", "<", "<=", ">", ">="
-  ],
-  "requireSpaceAfterBinaryOperators": [
-    "=", "+", "+=", "-", "-=", "/", "/=", "*", "*=", "===", "!==", "<", "<=", ">", ">="
-  ],
-  "disallowKeywords": ["with"],
-  "disallowMultipleLineStrings": true,
-  "disallowMixedSpacesAndTabs": "smart",
-  "disallowTrailingWhitespace": true,
-  "disallowTrailingComma": true,
-  "disallowKeywordsOnNewLine": ["else"],
-  "requireLineFeedAtFileEnd": true,
-  "maximumLineLength": {
-    "value": 120,
-    "tabSize": 4,
-    "allowUrlComments": true,
-    "allowRegex": true
-  },
-  "requireCapitalizedConstructors": true,
-  "requireDotNotation": true,
-  "disallowYodaConditions": true,
-  "requireSpaceAfterLineComment": {
-    "allExcept": ["#", "="]
-  },
-  "disallowNewlineBeforeBlockStatements": true,
-  "validateQuoteMarks": {
-    "mark": "'",
-    "escape": true
-  },
-  "validateParameterSeparator": ", ",
-  "safeContextKeyword": ["that"]
-}
diff --git a/.jshintrc b/.jshintrc
deleted file mode 100644
index c1efecd573..0000000000
--- a/.jshintrc
+++ /dev/null
@@ -1,25 +0,0 @@
-
-{
-  "bitwise": true,
-  "curly": true,
-  "eqeqeq": true,
-  "es3": true,
-  "forin": false,
-  "freeze": true,
-  "newcap": true,
-  "noarg": true,
-  "noempty": true,
-  "nonbsp": true,
-  "undef": true,
-  "unused": true,
-  "strict": true,
-
-  "browser": true,
-  "devel": true,
-  "jquery": true,
-
-  "globals": {
-    "JSON": true,
-    "phpbb": true
-  }
-}
diff --git a/phpBB/adm/style/admin.js b/phpBB/adm/style/admin.js
index 74269e92e9..4f7f5a990b 100644
--- a/phpBB/adm/style/admin.js
+++ b/phpBB/adm/style/admin.js
@@ -7,12 +7,12 @@
 /**
 * Parse document block
 */
-function parse_document(container) 
+function parse_document(container)
 {
 	var test = document.createElement('div'),
 		oldBrowser = (typeof test.style.borderRadius == 'undefined');
 
-	delete test;
+	test.remove();
 
 	/**
 	* Navigation
@@ -92,7 +92,7 @@ function parse_document(container)
 				}
 			});
 		}
-		
+
 		headersLength = headers.length;
 
 		// Add header text to each cell as <dfn>
@@ -159,7 +159,7 @@ function parse_document(container)
 		if ($this.html() == '&nbsp;') {
 			$this.addClass('responsive-hide');
 		}
-		
+
 	});
 
 	/**
diff --git a/travis/check-js.sh b/travis/check-js.sh
new file mode 100755
index 0000000000..f0894ab280
--- /dev/null
+++ b/travis/check-js.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This file is part of the phpBB Forum Software package.
+#
+# @copyright (c) phpBB Limited <https://www.phpbb.com>
+# @license GNU General Public License, version 2 (GPL-2.0)
+#
+# For full copyright and license information, please see
+# the docs/CREDITS.txt file.
+#
+set -e
+set +x
+
+NOTESTS=$1
+
+if [ "$NOTESTS" == '1' ]
+then
+	npm install -g > /dev/null
+	npm install > /dev/null
+	set -x
+	node_modules/xo/cli.js "phpBB/adm/style/*.js"
+	node_modules/xo/cli.js "phpBB/assets/javascript/*.js"
+	node_modules/xo/cli.js "phpBB/style/all/js/*.js"
+	node_modules/xo/cli.js "phpBB/style/prosilver/template/*.js"
+fi