diff --git a/m4/opm_lapack.m4 b/m4/opm_lapack.m4
index b5fa5ca5..083ecf0b 100644
--- a/m4/opm_lapack.m4
+++ b/m4/opm_lapack.m4
@@ -1,4 +1,7 @@
 AC_DEFUN([OPM_LAPACK],
 [AC_REQUIRE([AC_F77_WRAPPERS])dnl
  AC_REQUIRE([AX_LAPACK])dnl
+ if test x"$ax_lapack_ok" != xyes; then
+ 	AC_MSG_ERROR([BLAS/LAPACK required, but not found.])
+ fi
 ])[]dnl