diff --git a/pitfall/pitfall/core.rkt b/pitfall/pitfall/core.rkt
index 8fada01d..495418f4 100644
--- a/pitfall/pitfall/core.rkt
+++ b/pitfall/pitfall/core.rkt
@@ -19,6 +19,7 @@
              current-font-size
              current-font
              registered-fonts
+             font-count
              line-gap
              x
              y
diff --git a/pitfall/pitfall/font.rkt b/pitfall/pitfall/font.rkt
index 70640318..1441ebd5 100644
--- a/pitfall/pitfall/font.rkt
+++ b/pitfall/pitfall/font.rkt
@@ -56,7 +56,8 @@
   (match (hash-ref (pdf-font-families doc) cache-key #f) ; check if the font is already in the PDF
     [(? values val) (set-pdf-current-font! doc val)]
     [_ ; if not, load the font
-     (define font-index (add1 (length (hash-keys (pdf-font-families doc)))))
+     (define font-index (add1 (pdf-font-count doc)))
+     (set-pdf-font-count! doc font-index)
      (define id (string->symbol (format "F~a" font-index)))
      (set-pdf-current-font! doc (open-pdf-font src id))
      ;; check for existing font families with the same name already in the PDF
diff --git a/pitfall/pitfall/pdf.rkt b/pitfall/pitfall/pdf.rkt
index e80a44c5..1c1fd9ce 100644
--- a/pitfall/pitfall/pdf.rkt
+++ b/pitfall/pitfall/pdf.rkt
@@ -47,6 +47,7 @@
   (define current-font-size 12)
   (define current-font #false)
   (define registered-fonts (make-hash))
+  (define font-count 0)
   (define line-gap 0)
   (define x 0)
   (define y 0)
@@ -66,6 +67,7 @@
                        current-font-size
                        current-font
                        registered-fonts
+                       font-count
                        line-gap
                        x
                        y