diff --git a/sysutils/bareos23-server/files/patch-core_src_stored_backends_dedupable_volume.cc b/sysutils/bareos23-server/files/patch-core_src_stored_backends_dedupable_volume.cc
new file mode 100644
index 000000000000..0462f219f117
--- /dev/null
+++ b/sysutils/bareos23-server/files/patch-core_src_stored_backends_dedupable_volume.cc
@@ -0,0 +1,13 @@
+--- core/src/stored/backends/dedupable/volume.cc.orig	2025-09-18 21:46:06 UTC
++++ core/src/stored/backends/dedupable/volume.cc
+@@ -228,8 +228,8 @@ data::data(open_context ctx, const config& conf)
+ 
+   raii_fd bfd = OpenRelative(ctx, bf.relpath.c_str());
+   raii_fd pfd = OpenRelative(ctx, pf.relpath.c_str());
+-  blocks = decltype(blocks){ctx.read_only, bfd.fileno(), bf.End};
+-  parts = decltype(parts){ctx.read_only, pfd.fileno(), pf.End};
++  blocks = decltype(blocks){ctx.read_only, bfd.fileno(), static_cast<size_t>(bf.End)};
++  parts = decltype(parts){ctx.read_only, pfd.fileno(), static_cast<size_t>(pf.End)};
+   fds.emplace_back(std::move(bfd));
+   fds.emplace_back(std::move(pfd));
+