diff --git a/Makefile b/Makefile
index 8b4aaae..fdb2810 100644
--- a/Makefile
+++ b/Makefile
@@ -1,20 +1,20 @@
-PREFIX ?= /usr/local
-BINPREFIX ?= "$(PREFIX)/bin"
-LIBPREFIX ?= "$(PREFIX)/lib"
-MANPREFIX ?= "$(PREFIX)/share/man/man1"
-SYSCONFDIR ?= $(PREFIX)/etc
+prefix      := /usr/local
+exec_prefix := $(prefix)
+bindir      := $(exec_prefix)/bin
+libexecdir  := $(exec_prefix)/libexec
+sysconfdir  := $(prefix)/etc
+datarootdir := $(prefix)/share
+mandir      := $(datarootdir)/man
+man1dir     := $(mandir)/man1
 
 default: install
 
 install:
-	@mkdir -p $(DESTDIR)$(MANPREFIX)
-	@mkdir -p $(DESTDIR)$(BINPREFIX)
-	@mkdir -p $(DESTDIR)$(LIBPREFIX)/git-issue
-	install git-issue.sh $(DESTDIR)$(BINPREFIX)/git-issue
-	install lib/git-issue/import-export.sh $(DESTDIR)$(LIBPREFIX)/git-issue/import-export.sh
-	install -m 644 git-issue.1 $(DESTDIR)$(MANPREFIX)/
-	@mkdir -p $(DESTDIR)$(SYSCONFDIR)/bash_completion.d
-	install -m 644 gi-completion.sh $(DESTDIR)$(SYSCONFDIR)/bash_completion.d/git-issue
+	mkdir -p "$(bindir)" "$(libexecdir)/git-issue" "$(sysconfdir)/bash_completion.d" "$(man1dir)"
+	install git-issue.sh $(bindir)/git-issue
+	install lib/git-issue/import-export.sh $(libexecdir)/git-issue/import-export.sh
+	install -m 644 git-issue.1 $(man1dir)/
+	install -m 644 gi-completion.sh $(sysconfdir)/bash_completion.d/git-issue
 
 # Synchronize man page and usage with the contents of the README file
 sync-docs:
@@ -29,9 +29,9 @@ test:
 	./test.sh
 
 uninstall:
-	rm -f $(DESTDIR)$(BINPREFIX)/git-issue
-	rm -f $(DESTDIR)$(MANPREFIX)/git-issue.
-	rm -f $(DESTDIR)$(SYSCONFDIR)/bash_completion.d/git-issue
+	rm -f $(bindir)/git-issue
+	rm -f $(man1dir)/git-issue.
+	rm -f $(sysconfdir)/bash_completion.d/git-issue
 
 clean:
 
diff --git a/git-issue.sh b/git-issue.sh
index d32bc2f..a35baae 100755
--- a/git-issue.sh
+++ b/git-issue.sh
@@ -36,13 +36,13 @@ IFS=:
 # Set library path
 # shellcheck disable=SC2086
 # Rationale: Word splitting not an issue
-LIB_PATH="$(dirname $0)/../lib:$LD_LIBRARY_PATH:/usr/local/lib:/usr/lib"
+LIB_PATH="/usr/local/libexec/git-issue:$(dirname $0)/../libexec/git-issue:$(dirname $0)/../lib/git-issue"
 if [ "x$GIT_ISSUE_LIB_PATH" != x ] ; then
   LIB_PATH="$GIT_ISSUE_LIB_PATH"
 fi
 for i in ${LIB_PATH} ; do
-  if [ -d "${i}/git-issue" ] ; then
-    MY_LIB="${i}/git-issue"
+  if [ -d "${i}" ] && [ -f "${i}/import-export.sh" ] ; then
+    MY_LIB="${i}"
     break
   fi
 done