diff --git a/lib/child_process.js b/lib/child_process.js
index 0e3e04af0d6e32..c0ad3f5d99209e 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -503,12 +503,13 @@ function execFile(file, args, options, callback) {
       const length = encoding ?
         Buffer.byteLength(chunk, encoding) :
         chunk.length;
+      const slice = encoding ? StringPrototypeSlice :
+        (buf, ...args) => buf.slice(...args);
       stderrLen += length;
 
       if (stderrLen > options.maxBuffer) {
         const truncatedLen = options.maxBuffer - (stderrLen - length);
-        ArrayPrototypePush(_stderr,
-                           chunk.slice(0, truncatedLen));
+        ArrayPrototypePush(_stderr, slice(chunk, 0, truncatedLen));
 
         ex = new ERR_CHILD_PROCESS_STDIO_MAXBUFFER('stderr');
         kill();