diff --git a/util/nvramtool/Makefile b/util/nvramtool/Makefile
index f07ed7e..752e106 100644
--- a/util/nvramtool/Makefile
+++ b/util/nvramtool/Makefile
@@ -18,6 +18,11 @@
 	hexdump.o input_file.o layout.o layout_file.o lbtable.o   \
 	nvramtool.o opts.o reg_expr.o
 
+OS_ARCH        = $(shell uname)
+ifeq ($(OS_ARCH), Darwin)
+LDFLAGS = -framework DirectIO
+endif
+
 all: dep $(PROGRAM)
 
 $(PROGRAM): $(OBJS)
@@ -34,9 +39,10 @@
 	@$(CC) -MM *.c > .dependencies
 
 install: $(PROGRAM)
-	$(INSTALL) $(PROGRAM) $(PREFIX)/sbin
-	mkdir -p $(PREFIX)/share/man/man1
-	$(INSTALL) $(PROGRAM).8 $(PREFIX)/share/man/man8
+	mkdir -p $(DESTDIR)$(PREFIX)/sbin
+	$(INSTALL) $(PROGRAM) $(DESTDIR)$(PREFIX)/sbin
+	mkdir -p $(DESTDIR)$(PREFIX)/share/man/man8
+	$(INSTALL) $(PROGRAM).8 $(DESTDIR)$(PREFIX)/share/man/man8
 
 .PHONY: all clean distclean dep
 
diff --git a/util/nvramtool/common.h b/util/nvramtool/common.h
index a247380..c8ea92a 100644
--- a/util/nvramtool/common.h
+++ b/util/nvramtool/common.h
@@ -53,7 +53,12 @@
 #define INW(x) __extension__ ({ u_int tmp = (x); inw(tmp); })
 #define INL(x) __extension__ ({ u_int tmp = (x); inl(tmp); })
 #else
+#if defined(__GLIBC__)
 #include <sys/io.h>
+#endif
+#if (defined(__MACH__) && defined(__APPLE__))
+#include <DirectIO/darwinio.h>
+#endif
 #define OUTB outb
 #define OUTW outw
 #define OUTL outl
diff --git a/util/nvramtool/nvramtool.spec b/util/nvramtool/nvramtool.spec
index dcc23a9..2e3a4d0 100644
--- a/util/nvramtool/nvramtool.spec
+++ b/util/nvramtool/nvramtool.spec
@@ -33,9 +33,9 @@
 %install
 rm -rf "$RPM_BUILD_ROOT"
 mkdir -p "$RPM_BUILD_ROOT/usr/bin"
-mkdir -p "$RPM_BUILD_ROOT/usr/man/man1"
+mkdir -p "$RPM_BUILD_ROOT/usr/man/man8"
 cp nvramtool "$RPM_BUILD_ROOT/usr/bin"
-cp nvramtool.1.gz $RPM_BUILD_ROOT/usr/man/man1
+cp nvramtool.8.gz $RPM_BUILD_ROOT/usr/man/man8
 
 %clean
 rm -rf "$RPM_BUILD_ROOT"
@@ -45,4 +45,4 @@
 %doc ChangeLog README
 %doc README
 /usr/bin/nvramtool
-/usr/man/man1/nvramtool.1.gz
+/usr/man/man8/nvramtool.8.gz