diff --git a/tests/functional/pyocf/types/volume.py b/tests/functional/pyocf/types/volume.py
index 1a8155d..30eb174 100644
--- a/tests/functional/pyocf/types/volume.py
+++ b/tests/functional/pyocf/types/volume.py
@@ -147,7 +147,7 @@ class Volume:
                 print("{}".format(Volume._uuid_))
                 return -1
 
-            return Volume.open(ref, volume)
+            return Volume.s_open(ref, volume)
 
         @VolumeOps.CLOSE
         def _close(ref):
@@ -180,7 +180,7 @@ class Volume:
         return Volume._ops_[cls]
 
     @staticmethod
-    def open(ref, volume):
+    def s_open(ref, volume):
         if volume.opened:
             return -OcfErrorCode.OCF_ERR_NOT_OPEN_EXC
 
diff --git a/tests/functional/pyocf/types/volume_core.py b/tests/functional/pyocf/types/volume_core.py
index 6381de1..1de5098 100644
--- a/tests/functional/pyocf/types/volume_core.py
+++ b/tests/functional/pyocf/types/volume_core.py
@@ -18,7 +18,7 @@ class CoreVolume(ExpObjVolume):
             self.open()
 
     def open(self):
-        return Volume.open(self.lib.ocf_core_get_front_volume(self.core.handle), self)
+        return Volume.s_open(self.lib.ocf_core_get_front_volume(self.core.handle), self)
 
     def md5(self):
         return self._exp_obj_md5(4096)