diff --git a/.gitmodules b/.gitmodules
index 463b0a9..9f34e0d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -19,4 +19,3 @@
 [submodule "book/external/Sphinx-Image-Inverter"]
 	path = book/external/Sphinx-Image-Inverter
 	url = https://github.com/TeachBooks/Sphinx-Image-Inverter.git
-	branch = Module