diff --git a/.gitmodules b/.gitmodules
index 79d29be..60280c0 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -6,4 +6,4 @@
 	url = https://github.com/simonlindholm/asm-differ.git
 [submodule "tools/m2c"]
 	path = tools/m2c
-	url = git@github.com:matt-kempster/m2c.git
+	url = https://github.com/matt-kempster/m2c.git