diff --git a/packages/patched-derivations.nix b/packages/patched-derivations.nix
index 19357e2..5873bae 100644
--- a/packages/patched-derivations.nix
+++ b/packages/patched-derivations.nix
@@ -50,9 +50,8 @@ super: rec {
 
   prometheus-jitsi-exporter = patch super.prometheus-jitsi-exporter "patches/base/prometheus-jitsi-exporter";
 
-  s3ql = super.s3ql.overrideAttrs (old: {
+  s3ql = (patch super.s3ql "patches/base/s3ql").overrideAttrs (old: {
     propagatedBuildInputs = old.propagatedBuildInputs ++ [
-      super.python3Packages.packaging
       super.python3Packages.systemd
     ];
   });
diff --git a/patches/base/s3ql/metadata-accurate-length.patch b/patches/base/s3ql/metadata-accurate-length.patch
new file mode 100644
index 0000000..afa1ae5
--- /dev/null
+++ b/patches/base/s3ql/metadata-accurate-length.patch
@@ -0,0 +1,13 @@
+diff --git a/src/s3ql/database.py b/src/s3ql/database.py
+index 1c6df119..f3a47781 100644
+--- a/src/s3ql/database.py
++++ b/src/s3ql/database.py
+@@ -677,7 +677,7 @@ def upload_metadata(
+             )
+             obj = METADATA_OBJ_NAME % (blockno, params.seq_no)
+             fh.seek(blockno * blocksize)
+-            backend.write_fh(obj, fh, len_=blocksize)
++            backend.write_fh(obj, fh, len_=min(blocksize, db_size - blockno * blocksize))
+ 
+         if not update_params:
+             return