diff --git a/hwaccess.h b/hwaccess.h
index edf1738..2bc2927 100644
--- a/hwaccess.h
+++ b/hwaccess.h
@@ -76,6 +76,63 @@
 #endif
 #endif
 
+#if defined(__NetBSD__)
+  #define off64_t off_t
+  #define lseek64 lseek
+  #if defined(__i386__) || defined(__x86_64__)
+    #include <sys/types.h>
+    #include <machine/sysarch.h>
+    #if defined(__i386__)
+      #define iopl i386_iopl
+    #elif defined(__x86_64__)
+      #define iopl x86_64_iopl
+    #endif
+  #include <stdint.h>
+
+static inline void
+outb(uint8_t value, uint16_t port)
+{
+	asm volatile ("outb %b0,%w1": :"a" (value), "Nd" (port));
+}
+
+static inline uint8_t
+inb(uint16_t port)
+{
+	uint8_t value;
+	asm volatile ("inb %w1,%0":"=a" (value):"Nd" (port));
+	return value;
+}
+
+static inline void
+outw(uint16_t value, uint16_t port)
+{
+	asm volatile ("outw %w0,%w1": :"a" (value), "Nd" (port));
+}
+
+static inline uint16_t
+inw(uint16_t port)
+{
+	uint16_t value;
+	asm volatile ("inw %w1,%0":"=a" (value):"Nd" (port));
+	return value;
+}
+
+static inline void
+outl(uint32_t value, uint16_t port)
+{
+	asm volatile ("outl %0,%w1": :"a" (value), "Nd" (port));
+}
+
+static inline uint32_t
+inl(uint16_t port)
+{
+	uint32_t value;
+	asm volatile ("inl %1,%0":"=a" (value):"Nd" (port));
+	return value;
+}
+  #endif
+#endif
+
 #if defined(__FreeBSD__) || defined(__DragonFly__)
 extern int io_fd;
 #endif