diff --git a/Makefile b/Makefile
index 3536877..11f1954 100644
--- a/Makefile
+++ b/Makefile
@@ -22,9 +22,9 @@ OS_INCLUDE != test -e include/$(OS).mk && printf 'include/$(OS).mk\n' \
 	|| printf '/dev/null\n'
 
 # normalized prefix
-PREFIX_N != dirname $(PREFIX)/.
+PREFIX_N != realpath $(PREFIX)
 MANDIR != test $(PREFIX_N) = / && printf '/usr/share/man\n' \
-	|| printf '/share/man\n'
+	|| printf '$(PREFIX_N)/man\n'
 SYSEXITS != printf '\043include <sysexits.h>\n' | cpp -M - | tr ' ' '\n' \
 	| sed -n 's/sysexits\.h//p' || printf 'include\n'
 
@@ -54,9 +54,9 @@ clean:
 	rm -rf build dist
 
 dist: all docs
-	mkdir -p $(DESTDIR)/$(PREFIX)/bin $(DESTDIR)/$(PREFIX)/$(MANDIR)/man1
-	cp build/bin/* $(DESTDIR)/$(PREFIX)/bin
-	cp build/docs/*.1 $(DESTDIR)/$(PREFIX)/$(MANDIR)/man1
+	mkdir -p $(DESTDIR)/$(PREFIX_N)/bin $(DESTDIR)/$(MANDIR)/man1
+	cp build/bin/* $(DESTDIR)/$(PREFIX_N)/bin
+	cp build/docs/*.1 $(DESTDIR)/$(MANDIR)/man1
 
 .PHONY: install
 install: dist