diff --git a/lib/readline.js b/lib/readline.js
index 4e3d03f98111a0..4684fe91068b5c 100644
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -123,8 +123,7 @@ function Interface(input, output, completer, terminal) {
     terminal = input.terminal;
     historySize = input.historySize;
     if (input.tabSize !== undefined) {
-      const positive = true;
-      validateUint32(input.tabSize, 'tabSize', positive);
+      validateUint32(input.tabSize, 'tabSize', true);
       this.tabSize = input.tabSize;
     }
     removeHistoryDuplicates = input.removeHistoryDuplicates;