diff --git a/thin-provisioning/thin_check.cc b/thin-provisioning/thin_check.cc
index cb8d283..9ec4004 100644
--- a/thin-provisioning/thin_check.cc
+++ b/thin-provisioning/thin_check.cc
@@ -28,7 +28,6 @@
 #include "thin-provisioning/mapping_tree.h"
 #include "thin-provisioning/superblock.h"
 
-using namespace persistent_data;
 using namespace std;
 using namespace thin_provisioning;