diff --git a/tests/functional/pyocf/types/io.py b/tests/functional/pyocf/types/io.py
index dfc0471..0bfea6d 100644
--- a/tests/functional/pyocf/types/io.py
+++ b/tests/functional/pyocf/types/io.py
@@ -96,13 +96,13 @@ class Io(Structure):
         self.del_object()
 
     def submit(self):
-        return OcfLib.getInstance().ocf_core_submit_io_wrapper(byref(self))
+        return OcfLib.getInstance().ocf_volume_submit_io(byref(self))
 
     def submit_flush(self):
-        return OcfLib.getInstance().ocf_core_submit_flush_wrapper(byref(self))
+        return OcfLib.getInstance().ocf_volume_submit_flush(byref(self))
 
     def submit_discard(self):
-        return OcfLib.getInstance().ocf_core_submit_discard_wrapper(byref(self))
+        return OcfLib.getInstance().ocf_volume_submit_discard(byref(self))
 
     def set_data(self, data: Data, offset: int = 0):
         self.data = data
@@ -122,3 +122,12 @@ lib.ocf_core_new_io_wrapper.restype = c_void_p
 
 lib.ocf_io_set_data.argtypes = [POINTER(Io), c_void_p, c_uint32]
 lib.ocf_io_set_data.restype = c_int
+
+lib.ocf_volume_submit_io.argtypes = [POINTER(Io)]
+lib.ocf_volume_submit_io.restype = None
+
+lib.ocf_volume_submit_flush.argtypes = [POINTER(Io)]
+lib.ocf_volume_submit_flush.restype = None
+
+lib.ocf_volume_submit_discard.argtypes = [POINTER(Io)]
+lib.ocf_volume_submit_discard.restype = None