diff --git a/lnet/autoconf/lustre-lnet.m4 b/lnet/autoconf/lustre-lnet.m4
index 3ed69b48f3ad5215486eb1a824a9416ece40fa0d..30eda4502171a63e06751b700ddeee63808c6927 100644
--- a/lnet/autoconf/lustre-lnet.m4
+++ b/lnet/autoconf/lustre-lnet.m4
@@ -1150,7 +1150,7 @@ LB_LINUX_TRY_COMPILE([
 
 ],[
         AC_MSG_RESULT(yes)
-        AC_DEFINE(HAVE_KMEM_CACHE_n, 1,
+        AC_DEFINE(HAVE_KMEM_CACHE_S, 1,
                   [kernel has struct kmem_cache_s])
 ],[
         AC_MSG_RESULT(NO)