diff --git a/.gitmodules b/.gitmodules
index ec4547c..7e7959f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,9 +1,9 @@
 [submodule "thanm/libpng"]
 	path = extlib/libpng
-	url = https://github.com/glennrp/libpng.git
+	url = https://github.com/pnggroup/libpng.git
 [submodule "thanm/zlib-ng"]
 	path = extlib/zlib-ng
 	url = https://github.com/zlib-ng/zlib-ng.git
 [submodule "thtypes"]
 	path = extlib/thtypes
-	url = https://github.com/thpatch/thtypes
+	url = https://github.com/thpatch/thtypes.git
diff --git a/extlib/libpng b/extlib/libpng
index f135775..35d9f5e 160000
--- a/extlib/libpng
+++ b/extlib/libpng
@@ -1 +1 @@
-Subproject commit f135775ad4e5d4408d2e12ffcc71bb36e6b48551
+Subproject commit 35d9f5ea523cb4f9d677af4705e00ddd185ed10e