diff --git a/demo.scm b/demo.scm
index 8d32939..b1801c5 100644
--- a/demo.scm
+++ b/demo.scm
@@ -18,18 +18,14 @@
 		   (set-node-color (cdr pair) red)
 		   (cdr pair))))
        graph))
-
-(define djikstra-generator
+(define (make-graph-generator f)
   (generator
-   (djikstra graph 90 9 (lambda (visited heap)
+   (f graph 90 9 (lambda (visited heap)
 			  (yield (color-graph graph visited heap))))
    #f))
-(define a*-generator
-  (generator
-   (a* graph 90 9 (lambda (visited heap)
-		    (yield (color-graph graph visited heap))))
-   #f))
 
+(define djikstra-generator (make-graph-generator djikstra))
+(define a*-generator (make-graph-generator a*))
 (write-graphs-to-file "djikstra.webp" djikstra-generator)
 (write-graphs-to-file "astar.webp" a*-generator)
 
diff --git a/graphgif.scm b/graphgif.scm
index 507c079..8f540c6 100644
--- a/graphgif.scm
+++ b/graphgif.scm
@@ -33,12 +33,11 @@
   (lambda (node)
     (cairo-set-source cr black)
     (let-values ([(x y) (car+cdr (node-coords node))]
-		 [edges (node-edges node)])
+		 [(edges) (node-edges node)])
       (for-each
        (lambda (edge)
-	 (let* ([other (assq-ref graph edge)]
-		[ox (car (node-coords other))]
-		[oy (cdr (node-coords other))])
+	 (let*-values ([(other) (assq-ref graph edge)]
+		       [(ox oy) (car+cdr (node-coords other))])
 	   (cairo-move-to cr x y)
 	   (cairo-line-to cr ox oy)
 	   (cairo-stroke cr)))
@@ -48,7 +47,7 @@
   "Creates a closure that draws the nodes of graph using cr"
   (lambda (node)
     (let-values ([(x y) (car+cdr (node-coords node))]
-		 [color (or (node-color node) white)])
+		 [(color) (or (node-color node) white)])
       (cairo-arc cr x y 4. 0. tau)
       (cairo-set-source cr color)
       (cairo-fill-preserve cr)