diff --git a/test/parallel/test-child-process-buffering.js b/test/parallel/test-child-process-buffering.js
index a37e1dbbbd7574..1efa5a65f9cea8 100644
--- a/test/parallel/test-child-process-buffering.js
+++ b/test/parallel/test-child-process-buffering.js
@@ -2,8 +2,6 @@
 var common = require('../common');
 var assert = require('assert');
 
-var spawn = require('child_process').spawn;
-
 var pwd_called = false;
 var childClosed = false;
 var childExited = false;
diff --git a/test/parallel/test-child-process-cwd.js b/test/parallel/test-child-process-cwd.js
index e0e83b6007a815..f13da684fbdfe4 100644
--- a/test/parallel/test-child-process-cwd.js
+++ b/test/parallel/test-child-process-cwd.js
@@ -1,8 +1,6 @@
 'use strict';
 var common = require('../common');
 var assert = require('assert');
-var spawn = require('child_process').spawn;
-var path = require('path');
 
 var returns = 0;
 
diff --git a/test/parallel/test-child-process-exec-buffer.js b/test/parallel/test-child-process-exec-buffer.js
index 0ab05080a2cb87..b9727f0c63add5 100644
--- a/test/parallel/test-child-process-exec-buffer.js
+++ b/test/parallel/test-child-process-exec-buffer.js
@@ -9,7 +9,7 @@ var success_count = 0;
 var str = 'hello';
 
 // default encoding
-var child = exec('echo ' + str, function(err, stdout, stderr) {
+exec('echo ' + str, function(err, stdout, stderr) {
   assert.ok('string', typeof(stdout), 'Expected stdout to be a string');
   assert.ok('string', typeof(stderr), 'Expected stderr to be a string');
   assert.equal(str + os.EOL, stdout);
diff --git a/test/parallel/test-child-process-exec-cwd.js b/test/parallel/test-child-process-exec-cwd.js
index e253399b96ac30..c259ffffda3dee 100644
--- a/test/parallel/test-child-process-exec-cwd.js
+++ b/test/parallel/test-child-process-exec-cwd.js
@@ -16,7 +16,7 @@ if (common.isWindows) {
   dir = '/dev';
 }
 
-var child = exec(pwdcommand, {cwd: dir}, function(err, stdout, stderr) {
+exec(pwdcommand, {cwd: dir}, function(err, stdout, stderr) {
   if (err) {
     error_count++;
     console.log('error!: ' + err.code);
diff --git a/test/parallel/test-child-process-fork-dgram.js b/test/parallel/test-child-process-fork-dgram.js
index f700960490cbaa..86cd6576c73b98 100644
--- a/test/parallel/test-child-process-fork-dgram.js
+++ b/test/parallel/test-child-process-fork-dgram.js
@@ -25,7 +25,6 @@ if (common.isWindows) {
 }
 
 if (process.argv[2] === 'child') {
-  var childCollected = 0;
   var server;
 
   process.on('message', function removeMe(msg, clusterServer) {
diff --git a/test/parallel/test-child-process-fork-exec-path.js b/test/parallel/test-child-process-fork-exec-path.js
index 6a61bddd8a19a4..35a730b0da6c42 100644
--- a/test/parallel/test-child-process-fork-exec-path.js
+++ b/test/parallel/test-child-process-fork-exec-path.js
@@ -1,6 +1,5 @@
 'use strict';
 var assert = require('assert');
-var cp = require('child_process');
 var fs = require('fs');
 var path = require('path');
 var common = require('../common');
diff --git a/test/parallel/test-child-process-fork-ref2.js b/test/parallel/test-child-process-fork-ref2.js
index b7addea8f9c77d..42c43ed8882b78 100644
--- a/test/parallel/test-child-process-fork-ref2.js
+++ b/test/parallel/test-child-process-fork-ref2.js
@@ -1,6 +1,5 @@
 'use strict';
 require('../common');
-var assert = require('assert');
 var fork = require('child_process').fork;
 
 if (process.argv[2] === 'child') {
diff --git a/test/parallel/test-child-process-spawn-error.js b/test/parallel/test-child-process-spawn-error.js
index 1398dac165319c..4eaa45ee7aefb0 100644
--- a/test/parallel/test-child-process-spawn-error.js
+++ b/test/parallel/test-child-process-spawn-error.js
@@ -1,6 +1,5 @@
 'use strict';
 var common = require('../common');
-var fs = require('fs');
 var spawn = require('child_process').spawn;
 var assert = require('assert');
 
diff --git a/test/parallel/test-child-process-stdin.js b/test/parallel/test-child-process-stdin.js
index c12b24579375dc..4a371b83fb045b 100644
--- a/test/parallel/test-child-process-stdin.js
+++ b/test/parallel/test-child-process-stdin.js
@@ -18,30 +18,20 @@ var response = '';
 var exitStatus = -1;
 var closed = false;
 
-var gotStdoutEOF = false;
-
 cat.stdout.setEncoding('utf8');
 cat.stdout.on('data', function(chunk) {
   console.log('stdout: ' + chunk);
   response += chunk;
 });
 
-cat.stdout.on('end', function() {
-  gotStdoutEOF = true;
-});
-
-
-var gotStderrEOF = false;
+cat.stdout.on('end', common.mustCall(function() {}));
 
 cat.stderr.on('data', function(chunk) {
   // shouldn't get any stderr output
   assert.ok(false);
 });
 
-cat.stderr.on('end', function(chunk) {
-  gotStderrEOF = true;
-});
-
+cat.stderr.on('end', common.mustCall(function() {}));
 
 cat.on('exit', function(status) {
   console.log('exit event');
diff --git a/test/parallel/test-child-process-stdio-inherit.js b/test/parallel/test-child-process-stdio-inherit.js
index 8cf08a7bd5fa71..409c0af7ca0d31 100644
--- a/test/parallel/test-child-process-stdio-inherit.js
+++ b/test/parallel/test-child-process-stdio-inherit.js
@@ -31,5 +31,5 @@ function grandparent() {
 
 function parent() {
   // should not immediately exit.
-  var child = common.spawnCat({ stdio: 'inherit' });
+  common.spawnCat({ stdio: 'inherit' });
 }
diff --git a/test/parallel/test-child-process-stdio.js b/test/parallel/test-child-process-stdio.js
index 1ff6e4d914f7ec..d5fe6d43b64d5c 100644
--- a/test/parallel/test-child-process-stdio.js
+++ b/test/parallel/test-child-process-stdio.js
@@ -1,7 +1,6 @@
 'use strict';
 var common = require('../common');
 var assert = require('assert');
-var spawn = require('child_process').spawn;
 
 var options = {stdio: ['pipe']};
 var child = common.spawnPwd(options);
diff --git a/test/parallel/test-child-process-stdout-flush-exit.js b/test/parallel/test-child-process-stdout-flush-exit.js
index 577a33a05082f2..b76a7cb5e5a8e2 100644
--- a/test/parallel/test-child-process-stdout-flush-exit.js
+++ b/test/parallel/test-child-process-stdout-flush-exit.js
@@ -1,7 +1,6 @@
 'use strict';
 var common = require('../common');
 var assert = require('assert');
-var path = require('path');
 
 // if child process output to console and exit
 if (process.argv[2] === 'child') {