diff --git a/pkgs/by-name/zs/zsync/package.nix b/pkgs/by-name/zs/zsync/package.nix
index 934bf7e97a95..338a86a7bbaf 100644
--- a/pkgs/by-name/zs/zsync/package.nix
+++ b/pkgs/by-name/zs/zsync/package.nix
@@ -7,21 +7,18 @@
 
 stdenv.mkDerivation rec {
   pname = "zsync";
-  version = "0.6.2-unstable-2017-04-25";
+  version = "0.6.3-unstable-2025-05-29";
 
   src = fetchFromGitHub {
     owner = "cph6";
     repo = "zsync";
-    rev = "6cfe374f8f2310cbd624664ca98e5bb28244ba7a";
-    hash = "sha256-SnCzNDMyhMx+2JmgsrjtYDa31Ki1EWix9iBfaduDnro=";
+    rev = "a5cb28f923dd3cfdeb65e2930dd1faa727c2abf8";
+    hash = "sha256-gJs1P83AKWGipspeoFCSibZH+X6mmj3aL4+yjGO2YJo=";
   };
 
   sourceRoot = "${src.name}/c";
 
-  patches = [
-    ./remove-inexisting-rsumtest.patch
-    ./read-blocksums-declaration-fix.patch
-  ];
+  patches = [ ./remove-inexisting-rsumtest.patch ];
 
   makeFlags = [ "AR=${stdenv.cc.bintools.targetPrefix}ar" ];
 
diff --git a/pkgs/by-name/zs/zsync/read-blocksums-declaration-fix.patch b/pkgs/by-name/zs/zsync/read-blocksums-declaration-fix.patch
deleted file mode 100644
index d4e8e638af49..000000000000
--- a/pkgs/by-name/zs/zsync/read-blocksums-declaration-fix.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/libzsync/zsync.c b/libzsync/zsync.c
-index 793a426..783c349 100644
---- a/libzsync/zsync.c
-+++ b/libzsync/zsync.c
-@@ -116,7 +116,7 @@ struct zsync_state {
- };
- 
- static int zsync_read_blocksums(struct zsync_state *zs, FILE * f,
--                                int rsum_bytes, int checksum_bytes,
-+                                int rsum_bytes, unsigned int checksum_bytes,
-                                 int seq_matches);
- static int zsync_sha1(struct zsync_state *zs, int fh);
- static int zsync_recompress(struct zsync_state *zs);