diff --git a/src/core/fonts.js b/src/core/fonts.js
index aff4ac513..a94cc510a 100644
--- a/src/core/fonts.js
+++ b/src/core/fonts.js
@@ -680,7 +680,8 @@ var Font = (function FontClosure() {
 
   function isTrueTypeFile(file) {
     var header = file.peekBytes(4);
-    return readUint32(header, 0) === 0x00010000;
+    return (readUint32(header, 0) === 0x00010000 ||
+            bytesToString(header) === 'true');
   }
 
   function isTrueTypeCollectionFile(file) {