asterisk users - Jan 2007 - v140 ./configure not finding installed ssl

i'm building asterisk v140 on osx 10.4.8.

openssl is installed in /usr/local/ssl,

	which openssl
		/usr/local/ssl/bin/openssl
	openssl version
		OpenSSL 0.9.8d 28 Sep 2006

asterisk is config'd with,

	% ./configure                  \
	  --prefix=/usr/local/asterisk \
	  --enable-shared              \
	  --enable-static              \
	  --with-ssl=/usr/local/ssl

./configure fails @,

	(...)
	checking for ssl2_connect in -lssl... yes
	checking /usr/local/ssl/include/openssl/ssl.h usability... no
	checking /usr/local/ssl/include/openssl/ssl.h presence... no
	checking for /usr/local/ssl/include/openssl/ssl.h... no
	configure: ***
	configure: *** It appears that you do not have the ssl development
package installed.
	configure: *** Please install it to include OpenSSL support, or
re-run configure
	configure: *** without explicitly specifying --with-ssl

despite, checking,

	% ls -al /usr/local/ssl/include/openssl/ssl.h
		-rw-r--r-- 1 root wheel 79373 Sep 29 09:25
/usr/local/ssl/include/openssl/ssl.h

fwiw, ssl is used widely/successfully elsewhere.

suggestions as to what the issue is?

thanks.