2 files changed, 11 insertions, 5 deletions
diff --git a/apt-pkg/pkgcache.h b/apt-pkg/pkgcache.h
index f6d0ea097..d5d8fcad3 100644
--- a/apt-pkg/pkgcache.h
+++ b/apt-pkg/pkgcache.h
@@ -618,8 +618,9 @@ struct pkgCache::DescFile
    map_pointer<DescFile> NextFile;
    /** \brief position in the file */
    map_filesize_t Offset;         // File offset
-   /** @TODO document pkgCache::DescFile::Size */
-   map_filesize_t Size;
+#if APT_PKG_ABI <= 600
+   [[deprecated("No usage in src:apt, try MaxDescFileSize instead")]] map_filesize_t Size;
+#endif
 };
 									/*}}}*/
 // Version structure							/*{{{*/
diff --git a/apt-pkg/pkgcachegen.cc b/apt-pkg/pkgcachegen.cc
index aaa969a8d..76dea6266 100644
--- a/apt-pkg/pkgcachegen.cc
+++ b/apt-pkg/pkgcachegen.cc
@@ -949,9 +949,14 @@ bool pkgCacheGenerator::NewFileDesc(pkgCache::DescIterator &Desc,
    *Last = DF.MapPointer();
 
    DF->Offset = List.Offset();
-   DF->Size = List.Size();
-   if (Cache.HeaderP->MaxDescFileSize < DF->Size)
-      Cache.HeaderP->MaxDescFileSize = DF->Size;
+   auto const Size = List.Size();
+   if (Cache.HeaderP->MaxDescFileSize < Size)
+      Cache.HeaderP->MaxDescFileSize = Size;
+#if APT_PKG_ABI <= 600
+   APT_IGNORE_DEPRECATED_PUSH
+   DF->Size = Size;
+   APT_IGNORE_DEPRECATED_POP
+#endif
    Cache.HeaderP->DescFileCount++;
 
    return true;