diff --git a/plugins/perl/perl.plugin.zsh b/plugins/perl/perl.plugin.zsh
index 05f2a224..ff5230a0 100644
--- a/plugins/perl/perl.plugin.zsh
+++ b/plugins/perl/perl.plugin.zsh
@@ -1,3 +1,30 @@
+# For Perl older than 5.10.14, install local::lib.
+#   curl -L -C - -O http://search.cpan.org/CPAN/authors/id/A/AP/APEIRON/local-lib-1.008004.tar.gz
+#   tar xvf local-lib-1.008004.tar.gz
+#   cd local-lib-1.008004
+#   perl Makefile.PL --bootstrap=$HOME/Library/Perl/5.12
+#   make && make test && make install
+#
+# Install cpanminus:
+#   curl -L http://cpanmin.us | perl - --self-upgrade
+#
+if [[ "$OSTYPE" == darwin* ]]; then
+  # Perl is slow; cache its output.
+  cache_file="${0:h}/cache.zsh"
+  perl_path="$HOME/Library/Perl/5.12"
+  if [[ -f "$perl_path/lib/perl5/local/lib.pm" ]]; then
+    export MANPATH="$perl_path/man:$MANPATH"
+    if [[ ! -f "$cache_file" ]]; then
+      perl -I$perl_path/lib/perl5 -Mlocal::lib=$perl_path >! "$cache_file"
+      source "$cache_file"
+    else
+      source "$cache_file"
+    fi
+  fi
+  unset perl_path
+  unset cache_file
+fi
+
 # Aliases
 alias pbi='perlbrew install'
 alias pbl='perlbrew list'