diff --git a/m4/check_ssl.m4 b/m4/check_ssl.m4
index 3c68e0cae319212d1872c78fca856ca7541f7bb3..f0184605e1857fa0459d693274773846da9da370 100644
--- a/m4/check_ssl.m4
+++ b/m4/check_ssl.m4
@@ -18,7 +18,7 @@ AC_ARG_WITH(ssl,
     [check_ssl_dir="$withval"],
     [check_ssl_dir=])
 if test "x${PKGCONFIG}" != "x" -a "x${check_ssl_dir}" = "x" ; then
-    SSLDIR="`${PKGCONFIG} openssl --cflags-only-I | sed -e 's/-I//' -e 's/\/include\/openssl//' -e 's/\/include//' | grep '[a-z]' 2>/dev/null`"
+    SSLDIR="`${PKGCONFIG} openssl --cflags-only-I 2>/dev/null | sed -e 's/-I//' -e 's/\/include\/openssl//' -e 's/\/include//'`"
     if test "x${SSLDIR}" = "x" ; then
       if test -d "/usr/include/openssl" -o -f "/usr/include/ssl.h" ; then
         SSLDIR="/usr"