diff --git a/lib/internal/process/per_thread.js b/lib/internal/process/per_thread.js
index 63ebf2afb6ffee..f3a47744ccd187 100644
--- a/lib/internal/process/per_thread.js
+++ b/lib/internal/process/per_thread.js
@@ -164,7 +164,7 @@ function wrapProcessMethods(binding) {
   }
 
   function kill(pid, sig) {
-    var err;
+    let err;
 
     // eslint-disable-next-line eqeqeq
     if (pid != (pid | 0)) {