--- a/configure.ac
+++ b/configure.ac
@@ -364,7 +364,7 @@ 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
              0.*|1.*|2.0.*|2.1.*|2.2.*|2.3.*|2.4.*|2.5.*)