diff --git a/Configurations/unix-Makefile.tmpl b/Configurations/unix-Makefile.tmpl
index 5b6b1c7..4c8c916 100644
--- a/Configurations/unix-Makefile.tmpl
+++ b/Configurations/unix-Makefile.tmpl
@@ -818,7 +818,7 @@ _install_modules_deps: install_runtime_libs build_modules
 
 install_engines: _install_modules_deps
 	@[ -n "$(INSTALLTOP)" ] || (echo INSTALLTOP should not be empty; exit 1)
-	@$(PERL) $(SRCDIR)/util/mkdir-p.pl $(DESTDIR)$(ENGINESDIR)/
+	@[ -z "$(INSTALL_ENGINES)" ] || $(PERL) $(SRCDIR)/util/mkdir-p.pl $(DESTDIR)$(ENGINESDIR)/
 	@$(ECHO) "*** Installing engines"
 	@set -e; for e in dummy $(INSTALL_ENGINES); do \
 		if [ "$$e" = "dummy" ]; then continue; fi; \
@@ -842,7 +842,7 @@ uninstall_engines:
 
 install_modules: _install_modules_deps
 	@[ -n "$(INSTALLTOP)" ] || (echo INSTALLTOP should not be empty; exit 1)
-	@$(PERL) $(SRCDIR)/util/mkdir-p.pl $(DESTDIR)$(MODULESDIR)/
+	@[ -z "$(INSTALL_MODULES)" ] || $(PERL) $(SRCDIR)/util/mkdir-p.pl $(DESTDIR)$(MODULESDIR)/
 	@$(ECHO) "*** Installing modules"
 	@set -e; for e in dummy $(INSTALL_MODULES); do \
 		if [ "$$e" = "dummy" ]; then continue; fi; \