diff --git a/lib/_debugger.js b/lib/_debugger.js
index f1885b2e32f467..4c503d2f5480e9 100644
--- a/lib/_debugger.js
+++ b/lib/_debugger.js
@@ -101,7 +101,7 @@ Protocol.prototype.execute = function(d) {
       if (len - this.bodyStartByteIndex < this.contentLength) {
         break;
       }
-      // pass thru
+      // falls through
     case 'body':
       var resRawByteLength = Buffer.byteLength(res.raw, 'utf8');
 
@@ -125,7 +125,6 @@ Protocol.prototype.execute = function(d) {
 
     default:
       throw new Error('Unknown state');
-      break;
   }
 };
 
@@ -262,7 +261,7 @@ Client.prototype.req = function(req, cb) {
 
 Client.prototype.reqVersion = function(cb) {
   cb = cb || function() {};
-  this.req({ command: 'version' } , function(err, body, res) {
+  this.req({ command: 'version' }, function(err, body, res) {
     if (err) return cb(err);
     cb(null, res.body.body.V8Version, res.body.running);
   });
@@ -398,7 +397,7 @@ Client.prototype.reqFrameEval = function(expression, frame, cb) {
 // reqBacktrace(cb)
 // TODO: from, to, bottom
 Client.prototype.reqBacktrace = function(cb) {
-  this.req({ command: 'backtrace', arguments: { inlineRefs: true } } , cb);
+  this.req({ command: 'backtrace', arguments: { inlineRefs: true } }, cb);
 };
 
 
@@ -432,7 +431,7 @@ Client.prototype.reqScripts = function(cb) {
   var self = this;
   cb = cb || function() {};
 
-  this.req({ command: 'scripts' } , function(err, res) {
+  this.req({ command: 'scripts' }, function(err, res) {
     if (err) return cb(err);
 
     for (var i = 0; i < res.length; i++) {
diff --git a/lib/_http_incoming.js b/lib/_http_incoming.js
index 41ece371cdfbe6..aea665e80973c9 100644
--- a/lib/_http_incoming.js
+++ b/lib/_http_incoming.js
@@ -137,8 +137,10 @@ IncomingMessage.prototype._addHeaderLine = function(field, value, dest) {
       }
       break;
 
+    /* eslint-disable max-len */
     // list is taken from:
     // https://mxr.mozilla.org/mozilla/source/netwerk/protocol/http/src/nsHttpHeaderArray.cpp
+    /* eslint-enable max-len */
     case 'content-type':
     case 'content-length':
     case 'user-agent':
@@ -158,9 +160,9 @@ IncomingMessage.prototype._addHeaderLine = function(field, value, dest) {
 
     default:
       // make comma-separated list
-      if (dest[field] !== undefined)
+      if (dest[field] !== undefined) {
         dest[field] += ', ' + value;
-      else {
+      } else {
         dest[field] = value;
       }
   }
diff --git a/lib/_http_outgoing.js b/lib/_http_outgoing.js
index 88590551c9defb..bfebef21b69af6 100644
--- a/lib/_http_outgoing.js
+++ b/lib/_http_outgoing.js
@@ -85,8 +85,9 @@ OutgoingMessage.prototype.setTimeout = function(msecs, callback) {
     this.once('socket', function(socket) {
       socket.setTimeout(msecs);
     });
-  } else
+  } else {
     this.socket.setTimeout(msecs);
+  }
 };
 
 
diff --git a/lib/_http_server.js b/lib/_http_server.js
index 99903024c26d14..ae2bba035c8763 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -221,9 +221,11 @@ function Server(requestListener) {
     this.addListener('request', requestListener);
   }
 
+  /* eslint-disable max-len */
   // Similar option to this. Too lazy to write my own docs.
   // http://www.squid-cache.org/Doc/config/half_closed_clients/
   // http://wiki.squid-cache.org/SquidFaq/InnerWorkings#What_is_a_half-closed_filedescriptor.3F
+  /* eslint-enable max-len */
   this.httpAllowHalfOpen = false;
 
   this.addListener('connection', connectionListener);
diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 1de55597123d1b..bebbc80e2bf8dc 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -234,8 +234,9 @@ function howMuchToRead(n, state) {
     if (!state.ended) {
       state.needReadable = true;
       return 0;
-    } else
+    } else {
       return state.length;
+    }
   }
 
   return n;
@@ -774,7 +775,7 @@ Readable.prototype.wrap = function(stream) {
     if (this[i] === undefined && typeof stream[i] === 'function') {
       this[i] = function(method) { return function() {
         return stream[method].apply(stream, arguments);
-      }}(i);
+      }; }(i);
     }
   }
 
diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
index da65ddb90ae5ca..54f751abdf24ee 100644
--- a/lib/_stream_writable.js
+++ b/lib/_stream_writable.js
@@ -9,7 +9,6 @@ Writable.WritableState = WritableState;
 
 const util = require('util');
 const Stream = require('stream');
-const debug = util.debuglog('stream');
 
 util.inherits(Writable, Stream);
 
@@ -273,9 +272,9 @@ function writeOrBuffer(stream, state, chunk, encoding, cb) {
     } else {
       state.bufferedRequest = state.lastBufferedRequest;
     }
-  }
-  else
+  } else {
     doWrite(stream, state, false, len, chunk, encoding, cb);
+  }
 
   return ret;
 }
@@ -471,8 +470,9 @@ function finishMaybe(stream, state) {
       prefinish(stream, state);
       state.finished = true;
       stream.emit('finish');
-    } else
+    } else {
       prefinish(stream, state);
+    }
   }
   return need;
 }
diff --git a/lib/_tls_legacy.js b/lib/_tls_legacy.js
index 3348d7f92d951c..0a0c7bca7b9024 100644
--- a/lib/_tls_legacy.js
+++ b/lib/_tls_legacy.js
@@ -646,7 +646,7 @@ function onnewsession(key, session) {
 
     if (self.ssl)
       self.ssl.newSessionDone();
-  };
+  }
 }
 
 
diff --git a/lib/assert.js b/lib/assert.js
index 4a01e5c7f0b356..70e784a50c34b9 100644
--- a/lib/assert.js
+++ b/lib/assert.js
@@ -323,4 +323,4 @@ assert.doesNotThrow = function(block, /*optional*/message) {
   _throws.apply(this, [false].concat(pSlice.call(arguments)));
 };
 
-assert.ifError = function(err) { if (err) {throw err;}};
+assert.ifError = function(err) { if (err) throw err; };
diff --git a/lib/child_process.js b/lib/child_process.js
index 99da7cfbde94dc..34ce359f5b0ec5 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -169,7 +169,7 @@ SocketListSend.prototype._request = function(msg, cmd, callback) {
   function onclose() {
     self.slave.removeListener('internalMessage', onreply);
     callback(new Error('Slave closed before reply'));
-  };
+  }
 
   function onreply(msg) {
     if (!(msg.cmd === cmd && msg.key === self.key)) return;
@@ -177,7 +177,7 @@ SocketListSend.prototype._request = function(msg, cmd, callback) {
     self.slave.removeListener('internalMessage', onreply);
 
     callback(null, msg);
-  };
+  }
 
   this.slave.once('disconnect', onclose);
   this.slave.on('internalMessage', onreply);
diff --git a/lib/cluster.js b/lib/cluster.js
index 9a7900bc92b04e..ca1005b738068f 100644
--- a/lib/cluster.js
+++ b/lib/cluster.js
@@ -11,7 +11,7 @@ const SCHED_RR = 2;
 
 const uv = process.binding('uv');
 
-const cluster = new EventEmitter;
+const cluster = new EventEmitter();
 module.exports = cluster;
 cluster.Worker = Worker;
 cluster.isWorker = ('NODE_UNIQUE_ID' in process.env);
@@ -127,11 +127,10 @@ RoundRobinHandle.prototype.add = function(worker, send) {
   function done() {
     if (self.handle.getsockname) {
       var out = {};
-      var err = self.handle.getsockname(out);
+      self.handle.getsockname(out);
       // TODO(bnoordhuis) Check err.
       send(null, { sockname: out }, null);
-    }
-    else {
+    } else {
       send(null, null, null);  // UNIX socket.
     }
     self.handoff(worker);  // In case there are connections pending.
@@ -196,7 +195,7 @@ else
 function masterInit() {
   cluster.workers = {};
 
-  var intercom = new EventEmitter;
+  var intercom = new EventEmitter();
   cluster.settings = {};
 
   // XXX(bnoordhuis) Fold cluster.schedulingPolicy into cluster.settings?
diff --git a/lib/console.js b/lib/console.js
index 63e3c5e0bf1aa4..f9032e24a0fa44 100644
--- a/lib/console.js
+++ b/lib/console.js
@@ -73,7 +73,7 @@ Console.prototype.timeEnd = function(label) {
 Console.prototype.trace = function trace() {
   // TODO probably can to do this better with V8's debug object once that is
   // exposed.
-  var err = new Error;
+  var err = new Error();
   err.name = 'Trace';
   err.message = util.format.apply(this, arguments);
   Error.captureStackTrace(err, trace);
diff --git a/lib/crypto.js b/lib/crypto.js
index 10ff71e8547606..7ce89482d54b14 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -320,7 +320,7 @@ function Verify(algorithm, options) {
   if (!(this instanceof Verify))
     return new Verify(algorithm, options);
 
-  this._handle = new binding.Verify;
+  this._handle = new binding.Verify();
   this._handle.init(algorithm);
 
   stream.Writable.call(this, options);
diff --git a/lib/dgram.js b/lib/dgram.js
index 7d2592819a8e87..e80f78da076236 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -39,13 +39,13 @@ function lookup6(address, callback) {
 
 function newHandle(type) {
   if (type == 'udp4') {
-    var handle = new UDP;
+    var handle = new UDP();
     handle.lookup = lookup4;
     return handle;
   }
 
   if (type == 'udp6') {
-    var handle = new UDP;
+    var handle = new UDP();
     handle.lookup = lookup6;
     handle.bind = handle.bind6;
     handle.send = handle.send6;
@@ -301,8 +301,7 @@ Socket.prototype.send = function(buffer,
     if (ex) {
       if (callback) callback(ex);
       self.emit('error', ex);
-    }
-    else if (self._handle) {
+    } else if (self._handle) {
       var req = new SendWrap();
       req.buffer = buffer;  // Keep reference alive.
       req.length = length;
diff --git a/lib/dns.js b/lib/dns.js
index 9334800e4da5c4..28f1607b44ece2 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -239,7 +239,7 @@ function resolver(bindingName) {
     if (err) throw errnoException(err, bindingName);
     callback.immediately = true;
     return req;
-  }
+  };
 }
 
 
diff --git a/lib/events.js b/lib/events.js
index 064f3838b38ac9..63d79cea6d412c 100644
--- a/lib/events.js
+++ b/lib/events.js
@@ -307,8 +307,9 @@ EventEmitter.prototype.removeListener =
           if (--this._eventsCount === 0) {
             this._events = {};
             return this;
-          } else
+          } else {
             delete events[type];
+          }
         } else {
           spliceOne(list, position);
         }
diff --git a/lib/fs.js b/lib/fs.js
index b6b62265403ee8..4cdd0ef5e31456 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -40,7 +40,7 @@ function rethrow() {
   // Only enable in debug mode. A backtrace uses ~1000 bytes of heap space and
   // is fairly slow to generate.
   if (DEBUG) {
-    var backtrace = new Error;
+    var backtrace = new Error();
     return function(err) {
       if (err) {
         backtrace.stack = err.name + ': ' + err.message +
diff --git a/lib/net.js b/lib/net.js
index 6c9c9400dd6397..b261196119a9ed 100644
--- a/lib/net.js
+++ b/lib/net.js
@@ -431,7 +431,7 @@ Socket.prototype._destroy = function(exception, cb) {
       });
       self._writableState.errorEmitted = true;
     }
-  };
+  }
 
   if (this.destroyed) {
     debug('already destroyed, fire error callbacks');
@@ -1321,7 +1321,7 @@ Server.prototype.listen = function() {
 Server.prototype.address = function() {
   if (this._handle && this._handle.getsockname) {
     var out = {};
-    var err = this._handle.getsockname(out);
+    this._handle.getsockname(out);
     // TODO(bnoordhuis) Check err and throw?
     return out;
   } else if (this._pipeName) {
diff --git a/lib/querystring.js b/lib/querystring.js
index 09220a919e3edc..6aa188725ae25a 100644
--- a/lib/querystring.js
+++ b/lib/querystring.js
@@ -28,7 +28,7 @@ QueryString.unescapeBuffer = function(s, decodeSpaces) {
             break;
           case charCode('+'):
             if (decodeSpaces) c = charCode(' ');
-            // pass thru
+            // falls through
           default:
             out[outIndex++] = c;
             break;
diff --git a/lib/repl.js b/lib/repl.js
index 036b561f9c2a94..ddf3fecdfd56ea 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -318,7 +318,7 @@ function REPLServer(prompt, stream, eval_, useGlobal, ignoreUndefined) {
 
       // Display prompt again
       self.displayPrompt();
-    };
+    }
   });
 
   self.on('SIGCONT', function() {
diff --git a/lib/url.js b/lib/url.js
index 1683f905037c52..8da2f025dc8ca2 100644
--- a/lib/url.js
+++ b/lib/url.js
@@ -80,7 +80,7 @@ const querystring = require('querystring');
 function urlParse(url, parseQueryString, slashesDenoteHost) {
   if (url instanceof Url) return url;
 
-  var u = new Url;
+  var u = new Url();
   u.parse(url, parseQueryString, slashesDenoteHost);
   return u;
 }
diff --git a/lib/util.js b/lib/util.js
index a04c19c7353fdf..59283ce3740f04 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -27,6 +27,7 @@ exports.format = function(f) {
         } catch (_) {
           return '[Circular]';
         }
+        // falls through
       default:
         return x;
     }
diff --git a/src/node.js b/src/node.js
index d0d623c769bf06..bd5c1cb612448f 100644
--- a/src/node.js
+++ b/src/node.js
@@ -475,7 +475,7 @@
       if (process._exiting)
         return;
 
-      var args = undefined;
+      var args;
       if (arguments.length > 1) {
         args = [];
         for (var i = 1; i < arguments.length; i++)
@@ -496,8 +496,9 @@
           if (!process.emit('unhandledRejection', reason, promise)) {
             // Nobody is listening.
             // TODO(petkaantonov) Take some default action, see #830
-          } else
+          } else {
             hadListeners = true;
+          }
         }
       }
       return hadListeners;