diff --git a/scripts/Modules.build b/scripts/Modules.build
index 8650076..c20212a 100755
--- a/scripts/Modules.build
+++ b/scripts/Modules.build
@@ -7,11 +7,21 @@ TCL_DIR="${PSI_PREFIX}/Programming/Tcl/${TCL_VERSION}"
 
 PATH="${TCL_DIR}/bin:${PATH}"
 
+case ${OS} in
+Linux )
+	declare -x LIBS="-lz -lpthread"
+	;;
+Darwin )
+	declare -x LIBS="-lz -framework CoreFoundation"
+	;;
+esac
+
 function em.configure() {
-	CPPFLAGS="-DUSE_INTERP_ERRORLINE" LIBS="-lz -lpthread" "${MODULE_SRCDIR}"/configure \
+	CPPFLAGS="-DUSE_INTERP_ERRORLINE" "${MODULE_SRCDIR}"/configure \
 		--prefix="${PSI_PREFIX}/${MODULE_FAMILY}" \
 		--with-module-path="${PSI_PREFIX}/${PSI_MODULES_ROOT}" \
 		--with-tcl="${TCL_DIR}/lib" \
+		--without-x \
 		|| exit 1
 }
 # fake module command
@@ -23,5 +33,5 @@ module() {
 declare -rx CC=gcc
 
 em.add_to_family 'Tools'
-em.set_runtime_dependencies "Tcl/${TCL_VERSION}"
+em.set_build_dependencies "Tcl/${TCL_VERSION}"
 em.make_all