diff --git a/configure.ac b/configure.ac
index 2412d4f..8321915 100644
--- a/configure.ac
+++ b/configure.ac
@@ -232,6 +232,16 @@ if test "x$XSERVER_LIBPCIACCESS" = xyes; then
 fi
 AM_CONDITIONAL(XSERVER_LIBPCIACCESS, test "x$XSERVER_LIBPCIACCESS" = xyes)
 
+case $host_os in
+  *freebsd*)
+  AC_DEFINE(ALT_PRAGMA_PACK, 1, [Use alternate pragma pack]) ;;
+  *netbsd*)
+  AC_DEFINE(ALT_PRAGMA_PACK, 1, [Use alternate pragma pack]) ;;
+  *openbsd*)
+  AC_DEFINE(ALT_PRAGMA_PACK, 1, [Use alternate pragma pack]) ;;
+esac
+AM_CONDITIONAL(ALT_PRAGMA_PACK, test "x$ALT_PRAGMA_PACK" = xyes)
+
 AC_SUBST([XORG_CFLAGS])
 AC_SUBST([DRI_CFLAGS])
 AC_SUBST([moduledir])
diff --git a/src/Makefile.am b/src/Makefile.am
index 70c05e5..6fe0695 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -66,7 +66,11 @@ if USE_EXA
 RADEON_EXA_SOURCES = radeon_exa.c
 endif
 
+if ALT_PRAGMA_PACK
+AM_CFLAGS = @XORG_CFLAGS@ @DRI_CFLAGS@ @XMODES_CFLAGS@ -DDISABLE_EASF -DENABLE_ALL_SERVICE_FUNCTIONS -DATOM_BIOS -DATOM_BIOS_PARSER -DDRIVER_PARSER
+else
 AM_CFLAGS = @XORG_CFLAGS@ @DRI_CFLAGS@ @XMODES_CFLAGS@ -DDISABLE_EASF -DENABLE_ALL_SERVICE_FUNCTIONS -DATOM_BIOS -DATOM_BIOS_PARSER -DFGL_LINUX -DDRIVER_PARSER
+endif
 INCLUDES = -I$(srcdir)/AtomBios/includes
 
 ati_drv_la_LTLIBRARIES = ati_drv.la