diff --git a/m4/xerces_curl_prefix.m4 b/m4/xerces_curl_prefix.m4
index dbc68bf42d37671f058a1967ba43c303104984fc..314cd3227a1b1b0c2c2a8dd6108256408093ae2c 100644
--- a/m4/xerces_curl_prefix.m4
+++ b/m4/xerces_curl_prefix.m4
@@ -23,7 +23,7 @@ AC_DEFUN([XERCES_CURL_PREFIX],
 		if test x"$with_curl" != x"no"; then
 			search_list="$with_curl /usr/local /usr"
 			for i in $search_list; do
-				if test -r "$i/include/curl/easy.h"; then
+				if test -r "$i/include/curl/easy.h" -a -r "$i/include/curl/multi.h" ; then
 					xerces_cv_curl_prefix=$i
 					break
 				fi