diff --git a/configure.in b/configure.in
index f540671a..af8278e6 100644
--- a/configure.in
+++ b/configure.in
@@ -762,7 +762,7 @@ if test -n "$ac_cv_ps_varlist" ; then
 	AC_DEFINE_UNQUOTED(PS_COLS,$ac_cv_ps_cols,
 		[Number of columns in ps command])
 	EXTRAS="$EXTRAS check_procs check_nagios"
-	if echo "$ac_cv_ps_varlist" | grep -q "procetime"; then
+	if echo "$ac_cv_ps_varlist" | grep "procetime" >/dev/null; then
 		AC_DEFINE(PS_USES_PROCETIME,"yes",
 		          [Whether the ps utility uses the "procetime" field])
 	fi