diff --git a/src/core/fonts.js b/src/core/fonts.js
index fe8538ebb..fbcba6264 100644
--- a/src/core/fonts.js
+++ b/src/core/fonts.js
@@ -185,6 +185,25 @@ function getFontType(type, subtype) {
   }
 }
 
+// Some bad PDF generators, e.g. Scribus PDF, include glyph names
+// in a 'uniXXXX' format -- attempting to recover proper ones.
+function recoverGlyphName(name, glyphsUnicodeMap) {
+  if (glyphsUnicodeMap[name] !== undefined) {
+    return name;
+  }
+  // The glyph name is non-standard, trying to recover.
+  var unicode = getUnicodeForGlyph(name, glyphsUnicodeMap);
+  if (unicode !== -1) {
+    for (var key in glyphsUnicodeMap) {
+      if (glyphsUnicodeMap[key] === unicode) {
+        return key;
+      }
+    }
+  }
+  warn('Unable to recover a standard glyph name for: ' + name);
+  return name;
+}
+
 var Glyph = (function GlyphClosure() {
   function Glyph(fontChar, unicode, accent, width, vmetric, operatorListId,
                  isSpace, isInFont) {
@@ -2266,26 +2285,6 @@ var Font = (function FontClosure() {
         return false;
       }
 
-      // Some bad PDF generators, e.g. Scribus PDF, include glyph names
-      // in a 'uniXXXX' format -- attempting to recover proper ones.
-      function recoverGlyphName(name, glyphsUnicodeMap) {
-        if (glyphsUnicodeMap[name] !== undefined) {
-          return name;
-        }
-        // The glyph name is non-standard, trying to recover.
-        var unicode = getUnicodeForGlyph(name, glyphsUnicodeMap);
-        if (unicode !== -1) {
-          for (var key in glyphsUnicodeMap) {
-            if (glyphsUnicodeMap[key] === unicode) {
-              return key;
-            }
-          }
-        }
-        warn('Unable to recover a standard glyph name for: ' + name);
-        return name;
-      }
-
-
       if (properties.type === 'CIDFontType2') {
         var cidToGidMap = properties.cidToGidMap || [];
         var isCidToGidMapEmpty = cidToGidMap.length === 0;
@@ -2859,11 +2858,21 @@ function type1FontGlyphMapping(properties, builtInEncoding, glyphNames) {
   }
 
   // Lastly, merge in the differences.
-  var differences = properties.differences;
+  var differences = properties.differences, glyphsUnicodeMap;
   if (differences) {
     for (charCode in differences) {
       var glyphName = differences[charCode];
       glyphId = glyphNames.indexOf(glyphName);
+
+      if (glyphId === -1) {
+        if (!glyphsUnicodeMap) {
+          glyphsUnicodeMap = getGlyphsUnicode();
+        }
+        var standardGlyphName = recoverGlyphName(glyphName, glyphsUnicodeMap);
+        if (standardGlyphName !== glyphName) {
+          glyphId = glyphNames.indexOf(standardGlyphName);
+        }
+      }
       if (glyphId >= 0) {
         charCodeToGlyphId[charCode] = glyphId;
       } else {
diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
index d0b08ac30..7b256d168 100644
--- a/test/pdfs/.gitignore
+++ b/test/pdfs/.gitignore
@@ -26,6 +26,7 @@
 !issue7115.pdf
 !issue7200.pdf
 !issue7229.pdf
+!issue7439.pdf
 !filled-background.pdf
 !ArabicCIDTrueType.pdf
 !ThuluthFeatures.pdf
diff --git a/test/pdfs/issue7439.pdf b/test/pdfs/issue7439.pdf
new file mode 100644
index 000000000..03a6686be
Binary files /dev/null and b/test/pdfs/issue7439.pdf differ
diff --git a/test/test_manifest.json b/test/test_manifest.json
index ac342b40c..072e60191 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -1701,6 +1701,13 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue7439",
+       "file": "pdfs/issue7439.pdf",
+       "md5": "56682657990a894c66db26560d3039d7",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "bug867484",
       "file": "pdfs/bug867484.pdf",
       "md5": "347af7b0ef7279b1a7f43b03bfda4548",