diff --git a/tests/functional/pyocf/types/volume_cache.py b/tests/functional/pyocf/types/volume_cache.py
index 7c6199e..5865ec1 100644
--- a/tests/functional/pyocf/types/volume_cache.py
+++ b/tests/functional/pyocf/types/volume_cache.py
@@ -20,8 +20,8 @@ class CacheVolume(ExpObjVolume):
         if open:
             self.open()
 
-    def open(self):
-        return Volume.open(self.lib.ocf_cache_get_front_volume(self.cache.cache_handle), self)
+    def get_c_handle(self):
+        return self.cache.get_c_front_volume()
 
     def md5(self):
         out = self.cache.get_conf()
diff --git a/tests/functional/pyocf/types/volume_core.py b/tests/functional/pyocf/types/volume_core.py
index 1de5098..02a7695 100644
--- a/tests/functional/pyocf/types/volume_core.py
+++ b/tests/functional/pyocf/types/volume_core.py
@@ -17,8 +17,8 @@ class CoreVolume(ExpObjVolume):
         if open:
             self.open()
 
-    def open(self):
-        return Volume.s_open(self.lib.ocf_core_get_front_volume(self.core.handle), self)
+    def get_c_handle(self):
+        return self.core.get_c_front_volume()
 
     def md5(self):
         return self._exp_obj_md5(4096)
diff --git a/tests/functional/pyocf/types/volume_exp_obj.py b/tests/functional/pyocf/types/volume_exp_obj.py
index 984e5b3..9d92b5e 100644
--- a/tests/functional/pyocf/types/volume_exp_obj.py
+++ b/tests/functional/pyocf/types/volume_exp_obj.py
@@ -113,6 +113,10 @@ class ExpObjVolume(Volume):
 
         return read_buffer_all.md5()
 
+    def open(self):
+        handle = self.get_c_handle()
+        return Volume.s_open(handle, self)
+
 
 lib = OcfLib.getInstance()
 lib.ocf_volume_get_max_io_size.argtypes = [c_void_p]