diff -Nrup a/count.c b/count.c
--- a/count.c	2014-09-17 15:18:18.000000000 -0400
+++ b/count.c	2015-07-02 21:48:48.906419324 -0400
@@ -115,6 +115,16 @@ time_cmp(void *a, void *b)
 static int
 syscall_cmp(void *a, void *b)
 {
+	const char *name_a = sysent[*((int *) a)].sys_name;
+	const char *name_b = sysent[*((int *) b)].sys_name;
+
+	if (name_a == name_b)
+		return 0;
+	if (!name_a)
+		return -1;
+	if (!name_b)
+		return 1;
+
 	return strcmp(sysent[*((int *) a)].sys_name,
 		      sysent[*((int *) b)].sys_name);
 }