diff --git a/bin/pdf2htmlEX b/bin/pdf2htmlEX
index eec482c..96ba05e 100755
--- a/bin/pdf2htmlEX
+++ b/bin/pdf2htmlEX
@@ -12,6 +12,7 @@ echo -n "Converting fonts: "
 
 for f in *.ttf; do
     if [ -f $f ]; then
+        cp $f $f.old
         fontforge -script "${SCRIPT_DIR}/convert.pe" $f 2>/dev/null
         echo -n "."
     fi
@@ -19,6 +20,7 @@ done
 
 for f in *.pfa; do
     if [ -f $f ]; then
+        cp $f $f.old
         fontforge -script "${SCRIPT_DIR}/convert.pe" $f 2>/dev/null
         rm $f
         echo -n "."
diff --git a/src/HTMLRenderer.cc b/src/HTMLRenderer.cc
index fdea29d..92bbe0d 100644
--- a/src/HTMLRenderer.cc
+++ b/src/HTMLRenderer.cc
@@ -461,7 +461,20 @@ void HTMLRenderer::drawChar(GfxState *state, double x, double y,
     if(uLen > 0)
         cur_string->addUnicodes(state, x, y, dx, dy, u, uLen);
     else
+    {
+        if(nBytes > 0)
+        {
+            std::cerr << "Cannot map to Unicode!" << std::endl;
+            std::cerr << cur_fn_id << std::endl;
+            std::cerr << "*";
+            for(int i = 0; i < nBytes; ++i)
+            {
+                std::cerr << (int)(((char*)&code)[i]);
+            }
+            std::cerr << std::endl;
+        }
         cur_string->addChars(state, x, y, dx, dy, code, nBytes);
+    }
 }
 
 // TODO