diff --git a/Tremolo/bitwise.c b/Tremolo/bitwise.c
index 2182641..42be784 100644
--- a/Tremolo/bitwise.c
+++ b/Tremolo/bitwise.c
@@ -187,7 +187,7 @@
 
   b->tail=b->head=r;
   b->count=0;
-  if (b->head) {
+  if (b->head && r->length) {
     b->headptr=b->head->buffer->data+b->head->begin;
     b->headend=b->head->length;
   } else {
@@ -217,6 +217,8 @@
   unsigned long ret = 0;
   int BITS = bits;
 
+  if (!b->headptr) return 0;
+
   bits+=b->headbit;
 
   if(bits >= b->headend<<3){