diff --git a/m4/ax_dune_istl.m4 b/m4/ax_dune_istl.m4
index c1a6cd16..2f0fd55b 100644
--- a/m4/ax_dune_istl.m4
+++ b/m4/ax_dune_istl.m4
@@ -13,28 +13,27 @@ AC_DEFUN([OPM_DUNE_ISTL_PROGRAM_TEXT],
 
 
 AC_DEFUN([AX_DUNE_ISTL],
-[
-   AC_REQUIRE([AX_DUNE_COMMON])
+[AC_REQUIRE([AX_DUNE_COMMON])
 
-   AC_MSG_CHECKING(for installed dune-istl headers)
-
-   AC_LANG_PUSH([C++])[]dnl
+ AC_CACHE_CHECK(dnl
+[for installed dune-istl headers],dnl
+[ax_cv_dune_istl_available],dnl
+  [AC_LANG_PUSH([C++])[]dnl
 
    AC_LINK_IFELSE([OPM_DUNE_ISTL_PROGRAM_TEXT],dnl
                   [ax_cv_dune_istl_available=yes],dnl
                   [ax_cv_dune_istl_available=no])
 
    AC_LANG_POP([C++])[]dnl
+  ])[]dnl
 
-AS_IF([test "x$ax_cv_dune_istl_available" = "xyes" -a "x$ax_cv_dune_common_available"],dnl
+  AS_IF([test "x$ax_cv_dune_istl_available" = "xyes" -a \
+              "x$ax_cv_dune_common_available" = "xyes"],dnl
    [AC_DEFINE([HAVE_DUNE_ISTL], [1],dnl
-              [Define to 1 if `dune-istl' is available])[]dnl
-    AC_MSG_RESULT(yes)
-   ],dnl
-   [AC_MSG_RESULT(no)
+              [Define to 1 if `dune-istl' is available])
    ])[]dnl
 
   AM_CONDITIONAL([DUNE_ISTL],
-    [test "x$ax_cv_dune_istl_available" = "xyes" -a "x$ax_cv_dune_common_available"])
-
+    [test "x$ax_cv_dune_istl_available" = "xyes" -a \
+          "x$ax_cv_dune_common_available" = "xyes"])
 ])