diff --git a/archivers/zip.c b/archivers/zip.c
index 9eecb94..129b54a 100644
--- a/archivers/zip.c
+++ b/archivers/zip.c
@@ -368,7 +368,8 @@ static int ZIP_seek(FileHandle *handle, PHYSFS_uint64 offset)
                 return(0);
 
             inflateEnd(&finfo->stream);
-            memcpy(&finfo->stream, &str, sizeof (z_stream));
+            inflateCopy(&finfo->stream, &str);
+            inflateEnd(&str);
             finfo->uncompressed_position = finfo->compressed_position = 0;
         } /* if */