diff --git a/.gitmodules b/.gitmodules
index 452beaa..fb7b9fa 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -49,9 +49,15 @@
 [submodule "lispy"]
 	path = borg/lispy
 	url = https://github.com/abo-abo/lispy
+
 [submodule "pip-requirements"]
 	path = borg/pip-requirements
 	url = https://github.com/Wilfred/pip-requirements.el
+
+[submodule "mermaid-mode"]
+	path = borg/mermaid-mode
+	url = https://github.com/abrochard/mermaid-mode
+
 [submodule "pythonic"]
 	path = borg/pythonic
 	url = https://github.com/pythonic-emacs/pythonic
diff --git a/borg/mermaid-mode b/borg/mermaid-mode
new file mode 160000
index 0000000..93db0f7
--- /dev/null
+++ b/borg/mermaid-mode
@@ -0,0 +1 @@
+Subproject commit 93db0f75122de921966034990d60b19a71065d52