diff --git a/.eslintrc.js b/.eslintrc.js
index 900700831..788d0c44a 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -6,17 +6,17 @@ module.exports = {
         }
     },
     rules: {
-        "max-len": ["warn", {
+        "max-len": ["error", {
             code: 90,
             ignoreComments: true,
         }],
         curly: ["error", "multi-line"],
-        "require-jsdoc": ["warn", {
+        "require-jsdoc": ["error", {
             require: {
                 FunctionDeclaration: false,
             }
         }],
-        "valid-jsdoc": ["warn", {
+        "valid-jsdoc": ["error", {
             requireParamDescription: false,
             requireReturn: false,
             requireReturnDescription: false,
diff --git a/package.json b/package.json
index e310ae7b3..6c1d0f7e4 100644
--- a/package.json
+++ b/package.json
@@ -8,11 +8,11 @@
     "check": "jasmine-node spec --verbose --junitreport --captureExceptions",
     "gendoc": "jsdoc -r lib -P package.json -R README.md -d .jsdoc",
     "start": "babel -s -w -d lib src",
-    "build": "npm run lint && babel -s -d lib src && rimraf dist && mkdir dist && browserify --exclude olm browser-index.js -o dist/browser-matrix.js --ignore-missing && uglifyjs -c -m -o dist/browser-matrix.min.js dist/browser-matrix.js",
+    "build": "babel -s -d lib src && rimraf dist && mkdir dist && browserify --exclude olm browser-index.js -o dist/browser-matrix.js --ignore-missing && uglifyjs -c -m -o dist/browser-matrix.min.js dist/browser-matrix.js",
     "dist": "npm run build",
     "watch": "watchify --exclude olm browser-index.js -o dist/browser-matrix-dev.js -v",
     "lint": "eslint src spec",
-    "prepublish": "npm run build && git rev-parse HEAD > git-revision.txt"
+    "prepublish": "npm run lint && npm run build && git rev-parse HEAD > git-revision.txt"
   },
   "repository": {
     "url": "https://github.com/matrix-org/matrix-js-sdk"