diff --git a/.gitmodules b/.gitmodules
index ee6da0683f651f483529d493d1020cb3ba96666c..dad2358c146ff2133e493dd44a244ecf7648370e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -28,6 +28,3 @@
 [submodule "ThirdParty/SwmmInterface"]
 	path = ThirdParty/SwmmInterface
 	url = https://github.com/ufz/SwmmInterface.git
-[submodule "web/themes/hugo-theme-bootstrap4-blog"]
-	path = web/themes/hugo-theme-bootstrap4-blog
-	url = https://github.com/alanorth/hugo-theme-bootstrap4-blog
diff --git a/web/themes/hugo-theme-bootstrap4-blog b/web/themes/hugo-theme-bootstrap4-blog
deleted file mode 160000
index 0e381ab120e760860bb6379170689e2ba3adf060..0000000000000000000000000000000000000000
--- a/web/themes/hugo-theme-bootstrap4-blog
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 0e381ab120e760860bb6379170689e2ba3adf060