diff --git a/libarchive/ffi.py b/libarchive/ffi.py
index 22b3711..7dc16b1 100644
--- a/libarchive/ffi.py
+++ b/libarchive/ffi.py
@@ -47,7 +47,7 @@
     c_ssize_t, c_void_p, c_void_p, POINTER(c_void_p)
 )
 SEEK_CALLBACK = CFUNCTYPE(
-    c_longlong, c_int, c_void_p, c_longlong, c_int
+    c_longlong, c_void_p, c_void_p, c_longlong, c_int
 )
 OPEN_CALLBACK = CFUNCTYPE(c_int, c_void_p, c_void_p)
 CLOSE_CALLBACK = CFUNCTYPE(c_int, c_void_p, c_void_p)
diff --git a/libarchive/read.py b/libarchive/read.py
index 6ab0e1a..ff7a408 100644
--- a/libarchive/read.py
+++ b/libarchive/read.py
@@ -65,9 +65,10 @@ def custom_reader(
     open_cb = OPEN_CALLBACK(open_func) if open_func else NO_OPEN_CB
     read_cb = READ_CALLBACK(read_func)
     close_cb = CLOSE_CALLBACK(close_func) if close_func else NO_CLOSE_CB
+    seek_cb = SEEK_CALLBACK(seek_func)
     with new_archive_read(format_name, filter_name, passphrase) as archive_p:
         if seek_func:
-            ffi.read_set_seek_callback(archive_p, SEEK_CALLBACK(seek_func))
+            ffi.read_set_seek_callback(archive_p, seek_cb)
         ffi.read_open(archive_p, None, open_cb, read_cb, close_cb)
         yield archive_read_class(archive_p)
 
@@ -143,9 +144,10 @@ def seek_func(archive_p, context, offset, whence):
     open_cb = NO_OPEN_CB
     read_cb = READ_CALLBACK(read_func)
     close_cb = NO_CLOSE_CB
+    seek_cb = SEEK_CALLBACK(seek_func)
     with new_archive_read(format_name, filter_name, passphrase) as archive_p:
         if stream.seekable():
-            ffi.read_set_seek_callback(archive_p, SEEK_CALLBACK(seek_func))
+            ffi.read_set_seek_callback(archive_p, seek_cb)
         ffi.read_open(archive_p, None, open_cb, read_cb, close_cb)
         yield ArchiveRead(archive_p)