diff --git a/dist/dhcp/includes/cf/netbsd.h b/dist/dhcp/includes/cf/netbsd.h
index 4ceefd3701d9..ae3272b2e293 100644
--- a/dist/dhcp/includes/cf/netbsd.h
+++ b/dist/dhcp/includes/cf/netbsd.h
@@ -108,7 +108,7 @@ extern int h_errno;
 #  include <net/if_types.h>
 #endif
 
-#if defined(__alpha__) || defined(__sparc64__) || defined(__x86_64__)
+#ifdef _LP64
 #define PTRSIZE_64BIT
 #endif