diff --git a/test/parallel/test-http-missing-header-separator-cr.js b/test/parallel/test-http-missing-header-separator-cr.js
index 15ef8195d19372..a1fa7a532f1606 100644
--- a/test/parallel/test-http-missing-header-separator-cr.js
+++ b/test/parallel/test-http-missing-header-separator-cr.js
@@ -26,7 +26,7 @@ server.listen(0, common.mustSucceed(() => {
   let response = '';
 
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   client.setEncoding('utf8');
diff --git a/test/parallel/test-http-server-close-all.js b/test/parallel/test-http-server-close-all.js
index cf7d90b868162d..c4c211d97979a0 100644
--- a/test/parallel/test-http-server-close-all.js
+++ b/test/parallel/test-http-server-close-all.js
@@ -31,8 +31,10 @@ server.listen(0, function() {
     const client2 = connect(port);
     let response = '';
 
+    client2.setEncoding('utf8');
+
     client2.on('data', common.mustCall((chunk) => {
-      response += chunk.toString('utf-8');
+      response += chunk;
 
       if (response.endsWith('0\r\n\r\n')) {
         assert(response.startsWith('HTTP/1.1 200 OK\r\nConnection: keep-alive'));
diff --git a/test/parallel/test-http-server-close-idle.js b/test/parallel/test-http-server-close-idle.js
index 5218212996b159..361ccf990fabcc 100644
--- a/test/parallel/test-http-server-close-idle.js
+++ b/test/parallel/test-http-server-close-idle.js
@@ -33,8 +33,10 @@ server.listen(0, function() {
     const client2 = connect(port);
     let response = '';
 
+    client2.setEncoding('utf8');
+
     client2.on('data', common.mustCall((chunk) => {
-      response += chunk.toString('utf-8');
+      response += chunk;
 
       if (response.endsWith('0\r\n\r\n')) {
         assert(response.startsWith('HTTP/1.1 200 OK\r\nConnection: keep-alive'));
diff --git a/test/parallel/test-http-server-headers-timeout-delayed-headers.js b/test/parallel/test-http-server-headers-timeout-delayed-headers.js
index dc0efc5855ad02..af4a5df4b7f530 100644
--- a/test/parallel/test-http-server-headers-timeout-delayed-headers.js
+++ b/test/parallel/test-http-server-headers-timeout-delayed-headers.js
@@ -33,8 +33,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   const errOrEnd = common.mustSucceed(function(err) {
diff --git a/test/parallel/test-http-server-headers-timeout-interrupted-headers.js b/test/parallel/test-http-server-headers-timeout-interrupted-headers.js
index ce38123c15b684..9d25940ec65cd1 100644
--- a/test/parallel/test-http-server-headers-timeout-interrupted-headers.js
+++ b/test/parallel/test-http-server-headers-timeout-interrupted-headers.js
@@ -33,8 +33,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   const errOrEnd = common.mustSucceed(function(err) {
diff --git a/test/parallel/test-http-server-headers-timeout-keepalive.js b/test/parallel/test-http-server-headers-timeout-keepalive.js
index ba82cb0e0c9cb1..1affc5a4befff4 100644
--- a/test/parallel/test-http-server-headers-timeout-keepalive.js
+++ b/test/parallel/test-http-server-headers-timeout-keepalive.js
@@ -47,8 +47,9 @@ server.listen(0, common.mustCall(() => {
   let second = false;
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCallAtLeast((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
 
     // First response has ended
     if (!second && response.endsWith('\r\n\r\n')) {
diff --git a/test/parallel/test-http-server-headers-timeout-pipelining.js b/test/parallel/test-http-server-headers-timeout-pipelining.js
index 658bdf9a3aaf1c..bfd5af6bcefc1f 100644
--- a/test/parallel/test-http-server-headers-timeout-pipelining.js
+++ b/test/parallel/test-http-server-headers-timeout-pipelining.js
@@ -33,8 +33,9 @@ server.listen(0, common.mustCall(() => {
   let second = false;
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCallAtLeast((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
 
     // First response has ended
     if (!second && response.endsWith('\r\n\r\n')) {
diff --git a/test/parallel/test-http-server-request-timeout-delayed-body.js b/test/parallel/test-http-server-request-timeout-delayed-body.js
index 91cb5a851bcfe3..ac2120ef393719 100644
--- a/test/parallel/test-http-server-request-timeout-delayed-body.js
+++ b/test/parallel/test-http-server-request-timeout-delayed-body.js
@@ -40,8 +40,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   client.resume();
diff --git a/test/parallel/test-http-server-request-timeout-delayed-headers.js b/test/parallel/test-http-server-request-timeout-delayed-headers.js
index ae4260ddeefa18..304a78b96a77d3 100644
--- a/test/parallel/test-http-server-request-timeout-delayed-headers.js
+++ b/test/parallel/test-http-server-request-timeout-delayed-headers.js
@@ -28,8 +28,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   const errOrEnd = common.mustSucceed(function(err) {
diff --git a/test/parallel/test-http-server-request-timeout-interrupted-body.js b/test/parallel/test-http-server-request-timeout-interrupted-body.js
index 3b147693d97550..aa4843a48373df 100644
--- a/test/parallel/test-http-server-request-timeout-interrupted-body.js
+++ b/test/parallel/test-http-server-request-timeout-interrupted-body.js
@@ -40,8 +40,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   const errOrEnd = common.mustSucceed(function(err) {
diff --git a/test/parallel/test-http-server-request-timeout-interrupted-headers.js b/test/parallel/test-http-server-request-timeout-interrupted-headers.js
index 45c773996be209..eb9914dad1f56a 100644
--- a/test/parallel/test-http-server-request-timeout-interrupted-headers.js
+++ b/test/parallel/test-http-server-request-timeout-interrupted-headers.js
@@ -28,8 +28,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   const errOrEnd = common.mustSucceed(function(err) {
diff --git a/test/parallel/test-http-server-request-timeout-keepalive.js b/test/parallel/test-http-server-request-timeout-keepalive.js
index fd460b86bd1ca9..215d3dbc086ccb 100644
--- a/test/parallel/test-http-server-request-timeout-keepalive.js
+++ b/test/parallel/test-http-server-request-timeout-keepalive.js
@@ -45,8 +45,9 @@ server.listen(0, common.mustCall(() => {
   let second = false;
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCallAtLeast((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
 
     // First response has ended
     if (!second && response.endsWith('\r\n\r\n')) {
diff --git a/test/parallel/test-http-server-request-timeout-pipelining.js b/test/parallel/test-http-server-request-timeout-pipelining.js
index 2647268b11fc87..e00840791a3773 100644
--- a/test/parallel/test-http-server-request-timeout-pipelining.js
+++ b/test/parallel/test-http-server-request-timeout-pipelining.js
@@ -27,8 +27,9 @@ server.listen(0, common.mustCall(() => {
   let second = false;
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCallAtLeast((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
 
     // First response has ended
     if (!second && response.endsWith('\r\n\r\n')) {
diff --git a/test/parallel/test-http-server-request-timeout-upgrade.js b/test/parallel/test-http-server-request-timeout-upgrade.js
index 0d95a8b22c2b04..ad4fbe5c5e9a03 100644
--- a/test/parallel/test-http-server-request-timeout-upgrade.js
+++ b/test/parallel/test-http-server-request-timeout-upgrade.js
@@ -33,8 +33,9 @@ server.listen(0, common.mustCall(() => {
   const client = connect(server.address().port);
   let response = '';
 
+  client.setEncoding('utf8');
   client.on('data', common.mustCallAtLeast((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }, 1));
 
   client.on('end', common.mustCall(() => {
diff --git a/test/parallel/test-http-server-request-timeouts-mixed.js b/test/parallel/test-http-server-request-timeouts-mixed.js
index 44c8d03e3c17ae..41b7542c1bdbed 100644
--- a/test/parallel/test-http-server-request-timeouts-mixed.js
+++ b/test/parallel/test-http-server-request-timeouts-mixed.js
@@ -43,8 +43,9 @@ function createClient(server) {
     completed: false
   };
 
+  request.client.setEncoding('utf8');
   request.client.on('data', common.mustCallAtLeast((chunk) => {
-    request.response += chunk.toString('utf-8');
+    request.response += chunk;
   }));
 
   request.client.on('end', common.mustCall(() => {
diff --git a/test/parallel/test-http-transfer-encoding-repeated-chunked.js b/test/parallel/test-http-transfer-encoding-repeated-chunked.js
index f38c625646c078..a5680af9586b79 100644
--- a/test/parallel/test-http-transfer-encoding-repeated-chunked.js
+++ b/test/parallel/test-http-transfer-encoding-repeated-chunked.js
@@ -34,7 +34,7 @@ server.listen(0, common.mustSucceed(() => {
   let response = '';
 
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   client.setEncoding('utf8');
diff --git a/test/parallel/test-http-transfer-encoding-smuggling.js b/test/parallel/test-http-transfer-encoding-smuggling.js
index 9cd611464fec08..50c44ca5fc62ab 100644
--- a/test/parallel/test-http-transfer-encoding-smuggling.js
+++ b/test/parallel/test-http-transfer-encoding-smuggling.js
@@ -35,7 +35,7 @@ server.listen(0, common.mustSucceed(() => {
   // Verify that the server listener is never called
 
   client.on('data', common.mustCall((chunk) => {
-    response += chunk.toString('utf-8');
+    response += chunk;
   }));
 
   client.setEncoding('utf8');
diff --git a/test/parallel/test-https-server-close-all.js b/test/parallel/test-https-server-close-all.js
index c388260db3b484..1c9092ff5c9237 100644
--- a/test/parallel/test-https-server-close-all.js
+++ b/test/parallel/test-https-server-close-all.js
@@ -42,8 +42,9 @@ server.listen(0, function() {
     const client2 = connect({ port, rejectUnauthorized: false });
     let response = '';
 
+    client2.setEncoding('utf8');
     client2.on('data', common.mustCall((chunk) => {
-      response += chunk.toString('utf-8');
+      response += chunk;
 
       if (response.endsWith('0\r\n\r\n')) {
         assert(response.startsWith('HTTP/1.1 200 OK\r\nConnection: keep-alive'));
diff --git a/test/parallel/test-https-server-close-idle.js b/test/parallel/test-https-server-close-idle.js
index eb5a8c3585bb96..7f093c47cd8609 100644
--- a/test/parallel/test-https-server-close-idle.js
+++ b/test/parallel/test-https-server-close-idle.js
@@ -44,8 +44,9 @@ server.listen(0, function() {
     const client2 = connect({ port, rejectUnauthorized: false });
     let response = '';
 
+    client2.setEncoding('utf8');
     client2.on('data', common.mustCall((chunk) => {
-      response += chunk.toString('utf-8');
+      response += chunk;
 
       if (response.endsWith('0\r\n\r\n')) {
         assert(response.startsWith('HTTP/1.1 200 OK\r\nConnection: keep-alive'));