diff --git a/fonts.js b/fonts.js
index 343583acd..7d9b48465 100644
--- a/fonts.js
+++ b/fonts.js
@@ -11,6 +11,7 @@ var kMaxWaitForFontFace = 1000;
 
 // Unicode Private Use Area
 var kCmapGlyphOffset = 0xE000;
+var kSizeOfGlyphArea = 0x1900;
 
 // PDF Glyph Space Units are one Thousandth of a TextSpace Unit
 // except for Type 3 fonts
@@ -1217,18 +1218,21 @@ var Font = (function Font() {
         }
 
         var encoding = properties.encoding, i;
+
+        // offsetting glyphs to avoid problematic unicode ranges
         for (i in encoding) {
           if (encoding.hasOwnProperty(i)) {
             var unicode = encoding[i].unicode;
-            if (unicode <= 0x1f || (unicode >= 127 && unicode <= 255))
-              encoding[i].unicode = unicode += kCmapGlyphOffset;
+            if (unicode <= 0x1f ||
+                (unicode >= 127 && unicode < kSizeOfGlyphArea))
+              encoding[i].unicode += kCmapGlyphOffset;
           }
         }
 
         var glyphs = [];
         for (i = 1; i < numGlyphs; i++) {
           glyphs.push({
-            unicode: i <= 0x1f || (i >= 127 && i <= 255) ?
+            unicode: i <= 0x1f || (i >= 127 && i < kSizeOfGlyphArea) ?
               i + kCmapGlyphOffset : i
           });
         }
diff --git a/test/pdfs/ThuluthFeatures.pdf b/test/pdfs/ThuluthFeatures.pdf
new file mode 100755
index 000000000..95e6b7419
Binary files /dev/null and b/test/pdfs/ThuluthFeatures.pdf differ
diff --git a/test/test_manifest.json b/test/test_manifest.json
index b45c9ac5c..d4936154c 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -69,6 +69,11 @@
        "rounds": 1,
        "type": "load"
     },
+    {  "id": "thuluthfont-pdf",
+       "file": "pdfs/ThuluthFeatures.pdf",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "wnv_chinese-pdf",
        "file": "pdfs/wnv_chinese.pdf",
        "link": true,