diff --git a/ext/libpng b/ext/libpng
index 0bce10dd..9ca83675 160000
--- a/ext/libpng
+++ b/ext/libpng
@@ -1 +1 @@
-Subproject commit 0bce10dd609039d169c1fe4be64bbe4f6ef8b6c8
+Subproject commit 9ca8367555544998196fe86c49eb700a839dc946
diff --git a/ext/zlib b/ext/zlib
index a836aa48..5a14818f 160000
--- a/ext/zlib
+++ b/ext/zlib
@@ -1 +1 @@
-Subproject commit a836aa48b243ba1d2445bcb92233316aabf73cdc
+Subproject commit 5a14818f31782cc4552a13e10a8bb0d0545d5548