diff --git a/configure.ac b/configure.ac
index 483937a9ce4b166410ee42e312b24b13551b5d6a..a798372c2f219a8da71f2b79321c140aba23e790 100644
--- a/configure.ac
+++ b/configure.ac
@@ -469,7 +469,7 @@ if test "$enable_warn" != "no"; then
              CFLAGS="$CFLAGS -Wall"
           ;;
 	  intel)
-             CFLAGS="$CFLAGS -w2"
+             CFLAGS="$CFLAGS -w2 -Wunused-variable"
           ;;
 	  *)
 	     AX_CFLAGS_WARN_ALL