@@ -163,10 +163,10 @@ uninstall-program: uninstall-exec uninstall-doc
163163# Install everything.
164164.PHONY: install-all uninstall-all
165165install-all: install-doc install-lib-doc
166− destdir=$(DESTDIR); destdir=$${destdir:-/}; \
166+ destdir=$(DESTDIR); \
167167 # Older Cabal versions have no '--destdir' option.
168168 if $(BUILDCMD) copy --help | grep -q '\-\-destdir'; then \
169− opt='--destdir=$$destdir'; \
169+ opt="--destdir=$${destdir-/}"; \
170170 else \
171171 opt="--copy-prefix=$${destdir}$(PREFIX)"; \
172172 fi; \