diff --git a/lib/tput.js b/lib/tput.js
index c579dec..7d944c1 100644
--- a/lib/tput.js
+++ b/lib/tput.js
@@ -2041,6 +2041,18 @@ Tput.prototype.detectBrokenACS = function(info) {
     return !!+process.env.NCURSES_NO_UTF8_ACS;
   }
 
+  if (process.env.TMUX != null) {
+    try {
+      var tver = cp.execFileSync('tmux', ['-V'], { encoding: 'utf8' });
+      tver = +tver.split(' ')[1].split('.')[0];
+    } catch (e) {
+      ;
+    }
+    if (tver == null || tver >= 2) {
+      return true;
+    }
+  }
+
   // If the terminal supports unicode, we don't need ACS.
   if (info.numbers['U8'] >= 0) {
     return !!info.numbers['U8'];