diff --git a/test/sequential/test-debugger-auto-resume.js b/test/sequential/test-debugger-auto-resume.js
index 8a25f5fc804e1a..bdfe45441a039b 100644
--- a/test/sequential/test-debugger-auto-resume.js
+++ b/test/sequential/test-debugger-auto-resume.js
@@ -20,7 +20,7 @@ addLibraryPath(process.env);
   const env = { ...process.env };
   env.NODE_INSPECT_RESUME_ON_START = '1';
 
-  const cli = startCLI([script], [], { env });
+  const cli = startCLI(['--port=0', script], [], { env });
 
   cli.waitForInitialBreak()
     .then(() => {
diff --git a/test/sequential/test-debugger-backtrace.js b/test/sequential/test-debugger-backtrace.js
index f362e98068f15e..d22e187514d2cf 100644
--- a/test/sequential/test-debugger-backtrace.js
+++ b/test/sequential/test-debugger-backtrace.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'backtrace.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-break.js b/test/sequential/test-debugger-break.js
index fdfe9bd3c40064..9c100d5e1a0e3b 100644
--- a/test/sequential/test-debugger-break.js
+++ b/test/sequential/test-debugger-break.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'break.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-breakpoint-exists.js b/test/sequential/test-debugger-breakpoint-exists.js
index 7be0ba657fa981..47621ee5ec0735 100644
--- a/test/sequential/test-debugger-breakpoint-exists.js
+++ b/test/sequential/test-debugger-breakpoint-exists.js
@@ -10,7 +10,7 @@ const startCLI = require('../common/debugger');
 // Test for "Breakpoint at specified location already exists" error.
 {
   const script = fixtures.path('debugger', 'three-lines.js');
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-clear-breakpoints.js b/test/sequential/test-debugger-clear-breakpoints.js
index 91349e105a1160..74623ec4371331 100644
--- a/test/sequential/test-debugger-clear-breakpoints.js
+++ b/test/sequential/test-debugger-clear-breakpoints.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'break.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-exceptions.js b/test/sequential/test-debugger-exceptions.js
index f20f35d4808a47..0615e804dd8523 100644
--- a/test/sequential/test-debugger-exceptions.js
+++ b/test/sequential/test-debugger-exceptions.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'exceptions.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-exec-scope.js b/test/sequential/test-debugger-exec-scope.js
index 9e5d2ac7ebaeeb..085f3c70a73411 100644
--- a/test/sequential/test-debugger-exec-scope.js
+++ b/test/sequential/test-debugger-exec-scope.js
@@ -10,7 +10,7 @@ const assert = require('assert');
 
 // exec .scope
 {
-  const cli = startCLI([fixtures.path('debugger/backtrace.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/backtrace.js')]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-exec.js b/test/sequential/test-debugger-exec.js
index 4057dd03785e7c..389cf9bb764add 100644
--- a/test/sequential/test-debugger-exec.js
+++ b/test/sequential/test-debugger-exec.js
@@ -10,7 +10,7 @@ const assert = require('assert');
 
 {
 
-  const cli = startCLI([fixtures.path('debugger/alive.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/alive.js')]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-heap-profiler.js b/test/sequential/test-debugger-heap-profiler.js
index 86eb9d9d0d232f..a9fedce9ee3360 100644
--- a/test/sequential/test-debugger-heap-profiler.js
+++ b/test/sequential/test-debugger-heap-profiler.js
@@ -17,7 +17,7 @@ const filename = path.join(tmpdir.path, 'node.heapsnapshot');
 // Heap profiler take snapshot.
 {
   const opts = { cwd: tmpdir.path };
-  const cli = startCLI([fixtures.path('debugger/empty.js')], [], opts);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/empty.js')], [], opts);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-help.js b/test/sequential/test-debugger-help.js
index e24f873212b589..0139b7b9428112 100644
--- a/test/sequential/test-debugger-help.js
+++ b/test/sequential/test-debugger-help.js
@@ -9,7 +9,7 @@ const startCLI = require('../common/debugger');
 const assert = require('assert');
 
 {
-  const cli = startCLI([fixtures.path('debugger/empty.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/empty.js')]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-list.js b/test/sequential/test-debugger-list.js
index 594874e140b306..6f2e36e763a651 100644
--- a/test/sequential/test-debugger-list.js
+++ b/test/sequential/test-debugger-list.js
@@ -8,7 +8,7 @@ const startCLI = require('../common/debugger');
 
 const assert = require('assert');
 
-const cli = startCLI([fixtures.path('debugger/three-lines.js')]);
+const cli = startCLI(['--port=0', fixtures.path('debugger/three-lines.js')]);
 
 (async () => {
   await cli.waitForInitialBreak();
diff --git a/test/sequential/test-debugger-low-level.js b/test/sequential/test-debugger-low-level.js
index f6d97f2dfe153d..170ff3c1987c59 100644
--- a/test/sequential/test-debugger-low-level.js
+++ b/test/sequential/test-debugger-low-level.js
@@ -9,7 +9,7 @@ const assert = require('assert');
 
 // Debugger agent direct access.
 {
-  const cli = startCLI([fixtures.path('debugger/three-lines.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/three-lines.js')]);
   const scriptPattern = /^\* (\d+): \S+debugger(?:\/|\\)three-lines\.js/m;
 
   function onFatal(error) {
diff --git a/test/sequential/test-debugger-object-type-remote-object.js b/test/sequential/test-debugger-object-type-remote-object.js
index 7404eae3963447..a055e8ce0fb9e4 100644
--- a/test/sequential/test-debugger-object-type-remote-object.js
+++ b/test/sequential/test-debugger-object-type-remote-object.js
@@ -8,7 +8,7 @@ const startCLI = require('../common/debugger');
 
 const assert = require('assert');
 
-const cli = startCLI([fixtures.path('debugger/empty.js')]);
+const cli = startCLI(['--port=0', fixtures.path('debugger/empty.js')]);
 
 (async () => {
   await cli.waitForInitialBreak();
diff --git a/test/sequential/test-debugger-preserve-breaks.js b/test/sequential/test-debugger-preserve-breaks.js
index fbc463af96a1e6..1d17b3ed962a03 100644
--- a/test/sequential/test-debugger-preserve-breaks.js
+++ b/test/sequential/test-debugger-preserve-breaks.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'three-lines.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-profile-command.js b/test/sequential/test-debugger-profile-command.js
index 06818c2132d9c5..da81dfc6e10569 100644
--- a/test/sequential/test-debugger-profile-command.js
+++ b/test/sequential/test-debugger-profile-command.js
@@ -10,7 +10,7 @@ const assert = require('assert');
 const fs = require('fs');
 const path = require('path');
 
-const cli = startCLI([fixtures.path('debugger/empty.js')]);
+const cli = startCLI(['--port=0', fixtures.path('debugger/empty.js')]);
 
 const rootDir = path.resolve(__dirname, '..', '..');
 
diff --git a/test/sequential/test-debugger-profile.js b/test/sequential/test-debugger-profile.js
index 992c6f71c00775..3eaf32431d5aae 100644
--- a/test/sequential/test-debugger-profile.js
+++ b/test/sequential/test-debugger-profile.js
@@ -14,7 +14,7 @@ function delay(ms) {
 
 // Profiles.
 {
-  const cli = startCLI([fixtures.path('debugger/empty.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/empty.js')]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-restart-message.js b/test/sequential/test-debugger-restart-message.js
index bcd06b4e230131..4b8a167a1626f6 100644
--- a/test/sequential/test-debugger-restart-message.js
+++ b/test/sequential/test-debugger-restart-message.js
@@ -14,7 +14,7 @@ const startCLI = require('../common/debugger');
 // Using `restart` should result in only one "Connect/For help" message.
 {
   const script = fixtures.path('debugger', 'three-lines.js');
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-run-after-quit-restart.js b/test/sequential/test-debugger-run-after-quit-restart.js
index a9da07dcdff8bd..2c56f7227aed69 100644
--- a/test/sequential/test-debugger-run-after-quit-restart.js
+++ b/test/sequential/test-debugger-run-after-quit-restart.js
@@ -13,7 +13,7 @@ const path = require('path');
 {
   const scriptFullPath = fixtures.path('debugger', 'three-lines.js');
   const script = path.relative(process.cwd(), scriptFullPath);
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-sb-before-load.js b/test/sequential/test-debugger-sb-before-load.js
index 586687800e8e90..996cf3aa527de1 100644
--- a/test/sequential/test-debugger-sb-before-load.js
+++ b/test/sequential/test-debugger-sb-before-load.js
@@ -17,7 +17,7 @@ const path = require('path');
   const otherScriptFullPath = fixtures.path('debugger', 'cjs', 'other.js');
   const otherScript = path.relative(process.cwd(), otherScriptFullPath);
 
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-scripts.js b/test/sequential/test-debugger-scripts.js
index c6d4e67920921d..1e2bc5d5bec2dc 100644
--- a/test/sequential/test-debugger-scripts.js
+++ b/test/sequential/test-debugger-scripts.js
@@ -11,7 +11,7 @@ const assert = require('assert');
 // List scripts.
 {
   const script = fixtures.path('debugger', 'three-lines.js');
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-use-strict.js b/test/sequential/test-debugger-use-strict.js
index ae82a9fc82352b..dce928697659ea 100644
--- a/test/sequential/test-debugger-use-strict.js
+++ b/test/sequential/test-debugger-use-strict.js
@@ -11,7 +11,7 @@ const assert = require('assert');
 // Test for files that start with strict directive.
 {
   const script = fixtures.path('debugger', 'use-strict.js');
-  const cli = startCLI([script]);
+  const cli = startCLI(['--port=0', script]);
 
   function onFatal(error) {
     cli.quit();
diff --git a/test/sequential/test-debugger-watchers.js b/test/sequential/test-debugger-watchers.js
index e856132b74e28a..a5681ab9d2b440 100644
--- a/test/sequential/test-debugger-watchers.js
+++ b/test/sequential/test-debugger-watchers.js
@@ -10,7 +10,7 @@ const assert = require('assert');
 
 // Stepping through breakpoints.
 {
-  const cli = startCLI([fixtures.path('debugger/break.js')]);
+  const cli = startCLI(['--port=0', fixtures.path('debugger/break.js')]);
 
   function onFatal(error) {
     cli.quit();