-ifneq "$(INSTALL_DOCS) $(INSTALL_SGML_DOCS)" ""
-install-docs:: $(INSTALL_DOCS) $(foreach i,$(INSTALL_SGML_DOCS),$(foreach j,$(SGMLDocWays),$i.$j))
+ifneq "$(INSTALL_DOCS)$(INSTALL_SGML_DOC)" ""
+install-docs:: $(INSTALL_DOCS) $(foreach j,$(SGMLDocWays),$(INSTALL_SGML_DOC).$j)