diff --git a/configure.ac b/configure.ac
index f8c67be6..9899a3bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -94,6 +94,11 @@ AC_ARG_WITH([install],
                    [Specify the full PATH to a BSD-compatible install]),
     [INSTALL=$withval])
 AC_PROG_INSTALL
+AC_CACHE_VAL([ac_cv_path_GREP],
+    [AC_ARG_WITH([grep],
+        AS_HELP_STRING([--with-grep=PATH],
+                       [Specify the full PATH to GNU grep]),
+        [ac_cv_path_GREP=$withval])])
 AC_PROG_GREP
 AC_PROG_EGREP
 AS_IF(