--- a/configure.ac
+++ b/configure.ac
@@ -300,7 +300,7 @@ case "${host_os}" in
         # Ok, this is linux. Check the kernel version
         AC_MSG_CHECKING([for the kernel version])
 
-        kernel=`uname -r`
+        kernel=${UNAME_R:-`uname -r`}
 
         case "${kernel}" in
              2.6.*|3.*)