diff --git a/utils.c b/utils.c
index 800aa2c..1504048 100644
--- a/utils.c
+++ b/utils.c
@@ -71,7 +71,7 @@
 
 // count number of positive members in a list.
 // NOTE: list must be guaranteed to end in 0
-unsigned int count_positive(unsigned int *list)
+unsigned int count_positive(unsigned char *list)
 {
 	unsigned int c;