Index: aclocal/tcltls_openssl.m4
==================================================================
--- aclocal/tcltls_openssl.m4
+++ aclocal/tcltls_openssl.m4
@@ -1,6 +1,22 @@
 AC_DEFUN([TCLTLS_SSL_OPENSSL], [
+	AC_ARG_WITH([openssl-dir],
+		AS_HELP_STRING(
+			[--with-openssl-dir=<dir>],
+			[path to root directory of OpenSSL or LibreSSL installation]
+		), [
+			if test -e "$withval/libssl.$SHOBJEXT"; then
+				TCLTLS_SSL_LIBS="-L$withval -lssl -lcrypto"
+				withval="`AS_DIRNAME(["$withval"])`"
+			else
+				TCLTLS_SSL_LIBS="-L$withval/lib -lssl -lcrypto"
+			fi
+			TCLTLS_SSL_CFLAGS="-I$withval/include"
+			TCLTLS_SSL_CPPFLAGS="-I$withval/include"
+		]
+	)
+
 	dnl Use pkg-config to find the libraries
 	AC_ARG_VAR([TCLTLS_SSL_LIBS], [libraries to pass to the linker for OpenSSL or LibreSSL])
 	AC_ARG_VAR([TCLTLS_SSL_CFLAGS], [C compiler flags for OpenSSL or LibreSSL])
 	AC_ARG_VAR([TCLTLS_SSL_CPPFLAGS], [C preprocessor flags for OpenSSL or LibreSSL])
 	if test -z "$TCLTLS_SSL_LIBS"; then