diff --git a/.gitmodules b/.gitmodules
index 90692c8..ba379f8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -217,3 +217,6 @@
 [submodule "site-lisp/pinentry"]
 	path = site-lisp/pinentry
 	url = https://github.com/ueno/pinentry-el.git
+[submodule "site-lisp/deflate"]
+	path = site-lisp/deflate
+	url = https://github.com/skuro/deflate.git
diff --git a/lisp/init-plantuml.el b/lisp/init-plantuml.el
index 323a0c8..8e8bae6 100644
--- a/lisp/init-plantuml.el
+++ b/lisp/init-plantuml.el
@@ -3,6 +3,7 @@
 (require 'init-package)
 (add-pkg-in-pkg-dir "plantuml-mode")
 (add-pkg-in-pkg-dir "dash")
+(add-pkg-in-pkg-dir "deflate")
 
 (autoload 'plantuml-mode "plantuml-mode" "" t)
 (add-to-list 'auto-mode-alist '("\\.\\(plantuml\\|pum\\|plu\\)\\'" . plantuml-mode))
diff --git a/site-lisp/deflate b/site-lisp/deflate
new file mode 160000
index 0000000..d386385
--- /dev/null
+++ b/site-lisp/deflate
@@ -0,0 +1 @@
+Subproject commit d3863855d213f73dc7a1a54736d94a75f8f7e9c5