diff --git a/.gitmodules b/.gitmodules
index bc868ff8..e2d16039 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,15 +1,13 @@
-[submodule "third-party/pugixml"]
-	path = third-party/pugixml
-	url = https://github.com/zeux/pugixml.git
+[submodule "third-party/libstudxml"]
+	path = third-party/libstudxml
+	url = http://scm.codesynthesis.com/libstudxml/libstudxml.git
 	branch = master
 
 [submodule "third-party/cxxtest"]
 	path = third-party/cxxtest
 	url = https://github.com/CxxTest/cxxtest
 	branch = master
+
 [submodule "third-party/utfcpp"]
 	path = third-party/utfcpp
 	url = https://github.com/nemtrif/utfcpp
-[submodule "third-party/Optional"]
-	path = third-party/Optional
-	url = https://github.com/akrzemi1/Optional
diff --git a/third-party/Optional b/third-party/Optional
deleted file mode 160000
index bd25a1ba..00000000
--- a/third-party/Optional
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit bd25a1baef048fc5d358927718d367e3f821963e
diff --git a/third-party/pugixml b/third-party/pugixml
deleted file mode 160000
index 384db6ba..00000000
--- a/third-party/pugixml
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 384db6ba29a77559d1c232011ddf7838ef891169