diff --git a/skeletons/asn_random_fill.c b/skeletons/asn_random_fill.c
index 39e7eaa..a9877cf 100644
--- a/skeletons/asn_random_fill.c
+++ b/skeletons/asn_random_fill.c
@@ -26,5 +26,5 @@
     assert(a <= b);
     assert((b-a) < RAND_MAX);
     if(a == b) return a;
-    return a + (random() % (b - a));
+    return a + (random() % (b - a + 1));
 }