diff --git a/lib/libmemstat/memstat_malloc.c b/lib/libmemstat/memstat_malloc.c
index b9b686f0777b..70320f5861d1 100644
--- a/lib/libmemstat/memstat_malloc.c
+++ b/lib/libmemstat/memstat_malloc.c
@@ -26,6 +26,7 @@
  * $FreeBSD$
  */
 
+#include <sys/cdefs.h>
 #include <sys/param.h>
 #include <sys/malloc.h>
 #include <sys/sysctl.h>
@@ -253,14 +254,14 @@ kread(kvm_t *kvm, void *kvm_pointer, void *address, size_t size,
 }
 
 static int
-kread_string(kvm_t *kvm, void *kvm_pointer, char *buffer, int buflen)
+kread_string(kvm_t *kvm, const void *kvm_pointer, char *buffer, int buflen)
 {
 	ssize_t ret;
 	int i;
 
 	for (i = 0; i < buflen; i++) {
-		ret = kvm_read(kvm, (unsigned long)kvm_pointer + i,
-		    &(buffer[i]), sizeof(char));
+		ret = kvm_read(kvm, __DECONST(unsigned long, kvm_pointer) +
+		    i, &(buffer[i]), sizeof(char));
 		if (ret < 0)
 			return (MEMSTAT_ERROR_KVM);
 		if ((size_t)ret != sizeof(char))