diff --git a/lib/tput.js b/lib/tput.js
index 189d928..df90749 100644
--- a/lib/tput.js
+++ b/lib/tput.js
@@ -2036,7 +2036,7 @@ Tput.prototype.detectUnicode = function() {
 Tput.prototype.detectBrokenACS = function(info) {
   // ncurses-compatible env variable.
   if (process.env.NCURSES_NO_UTF8_ACS != null) {
-    return +process.env.NCURSES_NO_UTF8_ACS;
+    return !!+process.env.NCURSES_NO_UTF8_ACS;
   }
 
   // If the terminal supports unicode, we don't need ACS.