diff --git a/configure.ac b/configure.ac
index 67994b2..e043c95 100644
--- a/configure.ac
+++ b/configure.ac
@@ -103,6 +103,24 @@ if test "$DRI" = yes; then
         AC_DEFINE(SISDRI_DEVEL,1,[Enable developmental DRI driver support])
 fi
 
+AC_ARG_ENABLE(xaa,
+              AS_HELP_STRING([--enable-xaa],
+                             [Enable legacy X Acceleration Architecture (XAA) [default=auto]]),
+              [XAA="$enableval"],
+              [XAA=auto])
+if test "x$XAA" != xno; then
+        save_CFLAGS=$CFLAGS
+        save_CPPFLAGS=$CPPFLAGS
+        CFLAGS=$XORG_CFLAGS
+        CPPFLAGS="$XORG_CFLAGS"
+        AC_CHECK_HEADERS([xaa.h], XAA=yes, XAA=no)
+        CFLAGS=$save_CFLAGS
+        CPPFLAGS=$save_CPPFLAGS
+fi
+AC_MSG_CHECKING([whether to include XAA support])
+AM_CONDITIONAL(XAA, test "x$XAA" = xyes)
+AC_MSG_RESULT([$XAA])
+
 # technically this should be a configure flag.  meh.
 AC_DEFINE(XF86EXA, 1, [Build support for Exa])
 
diff --git a/src/sis.h b/src/sis.h
index 5ea3eba..46fca2a 100644
--- a/src/sis.h
+++ b/src/sis.h
@@ -226,7 +226,7 @@
 #define INCL_YUV_BLIT_ADAPTOR	/* Include support for YUV->RGB blit adaptors (VRAM queue mode only) */
 #endif
 
-#if 1
+#ifdef HAVE_XAA_H
 #define SIS_USE_XAA		/* Include code for XAA */
 #endif