diff --git a/dewfile.json b/dewfile.json
index c7870214..58896861 100644
--- a/dewfile.json
+++ b/dewfile.json
@@ -6,7 +6,7 @@
             "url": "https://github.com/madler/zlib",
             "type": "git",
             "head": "master",
-            "ref": "cacf7f1d4e3d44d871b605da3b647f07d718623f"
+            "ref": "51b7f2abdade71cd9bb0e7a373ef2610ec6f9daf"
         },
         {
             "name": "assimp",