diff --git a/src/bin.js b/src/bin.js
index aa99ebb..0738618 100644
--- a/src/bin.js
+++ b/src/bin.js
@@ -58,7 +58,9 @@ Typr._bin = {
 		}
 		return s;
 	},
-	_tdec : typeof window !== 'undefined' && window["TextDecoder"] ? new window["TextDecoder"]() : null,
+	_tdec : function() {
+		return typeof window !== 'undefined' && window["TextDecoder"] ? new window["TextDecoder"]() : null;
+	},
 	readUTF8 : function(buff, p, l) {
 		var tdec = Typr._bin._tdec;
 		if(tdec && p==0 && l==buff.length) return tdec["decode"](buff);