diff --git a/configure.in.in b/configure.in.in
index a40c6d4..27aa668 100644
--- a/configure.in.in
+++ b/configure.in.in
@@ -12,7 +12,7 @@ m4_define([xfsm_version_minor], [5])
 m4_define([xfsm_version_micro], [91])
 m4_define([xfsm_version_nano], [])
 m4_define([xfsm_version_build], [@REVISION@])
-m4_define([xfsm_version_tag], [])
+m4_define([xfsm_version_tag], [svn])
 m4_define([xfsm_version], [xfsm_version_major().xfsm_version_minor().xfsm_version_micro()ifelse(xfsm_version_nano(), [], [], [.xfsm_version_nano()])ifelse(xfsm_version_tag(), [svn], [xfsm_version_tag()[-r]xfsm_version_build()], [])])
 
 dnl Initialize autoconf
@@ -48,7 +48,7 @@ AC_PROG_LIBTOOL()
 
 dnl check for standard header files
 AC_HEADER_STDC
-AC_CHECK_HEADERS([asm/unistd.h errno.h fcntl.h limits.h linux/ioprio.h \
+AC_CHECK_HEADERS([asm/unistd.h errno.h fcntl.h limits.h \
                   netdb.h signal.h stdarg.h sys/param.h sys/resource.h \
                   sys/socket.h sys/time.h sys/wait.h sys/utsname.h time.h \
                   unistd.h])
@@ -128,6 +128,21 @@ else
   AC_MSG_RESULT([yes])
 fi
 
+dnl check for linux/ioprio.h, and also check that the header actually
+dnl works, as some kernels have bad headers.  using AC_CHECK_HEADERS()
+dnl prints a scary warning with a request to report a bug if it fails,
+dnl but we don't want that.
+AC_MSG_CHECKING([whether linux/ioprio.h exists and actually works])
+AC_COMPILE_IFELSE([
+AC_INCLUDES_DEFAULT
+#include <linux/ioprio.h>
+                ], [linux_ioprio_works=yes], [linux_ioprio_works=no])
+AC_MSG_RESULT([$linux_ioprio_works])
+if test "x$linux_ioprio_works" = "xyes"; then
+  AC_DEFINE([HAVE_WORKING_LINUX_IOPRIO_H], [1],
+            [Defined if linux/ioprio.h not only exists, but works properly])
+fi
+
 AC_OUTPUT([
 Makefile
 xfce4-session.spec
diff --git a/xfce4-session/xfsm-manager.c b/xfce4-session/xfsm-manager.c
index 8bef5ac..626346f 100644
--- a/xfce4-session/xfsm-manager.c
+++ b/xfce4-session/xfsm-manager.c
@@ -51,15 +51,15 @@
 #  include <asm/unistd.h>
 #  include <sys/syscall.h>
 #  ifdef __NR_ioprio_set
-#    ifdef HAVE_LINUX_IOPRIO_H
+#    ifdef HAVE_WORKING_LINUX_IOPRIO_H
 #      include <linux/ioprio.h>
-#    else  /* if !HAVE_LINUX_IOPRIO_H */
+#    else  /* if !HAVE_WORKING_LINUX_IOPRIO_H */
 #      define IOPRIO_CLASS_SHIFT              (13)
 #      define IOPRIO_PRIO_MASK                ((1UL << IOPRIO_CLASS_SHIFT) - 1)
 #      define IOPRIO_PRIO_VALUE(class, data)  (((class) << IOPRIO_CLASS_SHIFT) | data)
 #      define IOPRIO_WHO_PROCESS              (1)
 #      define IOPRIO_CLASS_IDLE               (3)
-#    endif  /* !HAVE_LINUX_IOPRIO_H */
+#    endif  /* !HAVE_WORKING_LINUX_IOPRIO_H */
 #  endif  /* __NR_ioprio_set */
 #endif  /* HAVE_ASM_UNISTD_H */