diff --git a/Makefile.am b/Makefile.am
index 7e386f84c5..f50351b05b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,6 @@
 SUBDIRS = externals src scripts corepkgs doc misc tests
-EXTRA_DIST = substitute.mk nix.spec nix.spec.in bootstrap.sh svn-revision
+EXTRA_DIST = substitute.mk nix.spec nix.spec.in bootstrap.sh \
+  svn-revision nix.conf.example
 
 include ./substitute.mk
 
@@ -12,6 +13,11 @@ relname:
 	echo -n $(distdir) > relname
 
 install-data-local: init-state
+	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
+	$(INSTALL_DATA) nix.conf.example $(DESTDIR)$(sysconfdir)/nix
+	if ! test -e $(DESTDIR)$(sysconfdir)/nix/nix.conf; then \
+		$(INSTALL_DATA) nix.conf.example $(DESTDIR)$(sysconfdir)/nix/nix.conf; \
+	fi
 
 if INIT_STATE
 if SETUID_HACK
diff --git a/nix.conf.example b/nix.conf.example
new file mode 100644
index 0000000000..1af5df952b
--- /dev/null
+++ b/nix.conf.example
@@ -0,0 +1,30 @@
+### Option `gc-keep-outputs'
+#
+# If `true', the garbage collector will keep the outputs of
+# non-garbage derivations.  If `false' (default), outputs will be
+# deleted unless they are GC roots themselves (or reachable from other
+# roots).
+# 
+# In general, outputs must be registered as roots separately.
+# However, even if the output of a derivation is registered as a root,
+# the collector will still delete store paths that are used only a
+# build time (e.g., the C compiler, or source tarballs downloaded from
+# the network).  To prevent it from doing so, set this option to
+# `true'.
+gc-keep-outputs = false
+
+
+### Option `gc-keep-derivations'
+#
+# If `true' (default), the garbage collector will keep the derivations
+# from which non-garbage store paths were built.  If `false', they
+# will be deleted unless explicitly registered as a root (or reachable
+# from other roots).
+#
+# Keeping derivation around is useful for querying and traceability
+# (e.g., it allows you to ask with what dependencies or options a
+# store path was built), so by default this option is on.  Turn it off
+# to safe a bit of disk space (or a lot if `gc-keep-outputs' is also
+# turned on).
+gc-keep-derivations = true
+