diff --git a/flashrom.c b/flashrom.c
index d89860a..e1be398 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1121,8 +1121,8 @@
 		return 1;
 	}
 	if (image_stat.st_size != size) {
-		msg_gerr("Error: Image size (%ld B) doesn't match the flash chip's size (%ld B)!\n",
-			 image_stat.st_size, size);
+		msg_gerr("Error: Image size (%jd B) doesn't match the flash chip's size (%ld B)!\n",
+			 (intmax_t)image_stat.st_size, size);
 		fclose(image);
 		return 1;
 	}
diff --git a/hwaccess.c b/hwaccess.c
index f0b2f63..598aa67 100644
--- a/hwaccess.c
+++ b/hwaccess.c
@@ -28,7 +28,8 @@
 
 #define IS_BSD	(defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__OpenBSD__))
 #define IS_LINUX	(defined(__gnu_linux__) || defined(__linux__))
-#if !(IS_BSD || IS_LINUX || defined(__DJGPP__) || defined(__LIBPAYLOAD__) || defined(__sun))
+#define IS_MACOSX	(defined(__APPLE__) && defined(__MACH__))
+#if !(IS_BSD || IS_LINUX || IS_MACOSX || defined(__DJGPP__) || defined(__LIBPAYLOAD__) || defined(__sun))
 #error "Unknown operating system"
 #endif
 
@@ -72,7 +73,7 @@
 	sysi86(SI86V86, V86SC_IOPL, 0);
 #elif IS_BSD
 	close(io_fd);
-#elif IS_LINUX
+#elif IS_LINUX || IS_MACOSX
 	iopl(0);
 #endif
 	return 0;
@@ -87,7 +88,7 @@
 	if (sysi86(SI86V86, V86SC_IOPL, PS_IOPL) != 0) {
 #elif IS_BSD
 	if ((io_fd = open("/dev/io", O_RDWR)) < 0) {
-#elif IS_LINUX
+#elif IS_LINUX || IS_MACOSX
 	if (iopl(3) != 0) {
 #endif
 		msg_perr("ERROR: Could not get I/O privileges (%s).\n"
diff --git a/hwaccess.h b/hwaccess.h
index dc52118..714a660 100644
--- a/hwaccess.h
+++ b/hwaccess.h
@@ -189,8 +189,6 @@
    * versions. Use machine/cpufunc.h only for plain FreeBSD/DragonFlyBSD.
    */
   #include <machine/cpufunc.h>
-  #define off64_t off_t
-  #define lseek64 lseek
   #define OUTB(x, y) do { u_int outb_tmp = (y); outb(outb_tmp, (x)); } while (0)
   #define OUTW(x, y) do { u_int outw_tmp = (y); outw(outw_tmp, (x)); } while (0)
   #define OUTL(x, y) do { u_int outl_tmp = (y); outl(outl_tmp, (x)); } while (0)
@@ -201,8 +199,6 @@
 #if defined(__MACH__) && defined(__APPLE__)
     /* Header is part of the DirectHW library. */
     #include <DirectHW/DirectHW.h>
-    #define off64_t off_t
-    #define lseek64 lseek
 #endif
 #if defined (__sun) && (defined(__i386) || defined(__amd64))
   /* Note different order for outb */
@@ -241,8 +237,6 @@
 #endif
 
 #if defined(__NetBSD__) || defined (__OpenBSD__)
-  #define off64_t off_t
-  #define lseek64 lseek
   #if defined(__i386__) || defined(__x86_64__)
     #include <sys/types.h>
     #include <machine/sysarch.h>