diff --git a/src/fs/luks.cpp b/src/fs/luks.cpp
index 64b305b..6cfe951 100644
--- a/src/fs/luks.cpp
+++ b/src/fs/luks.cpp
@@ -338,7 +338,8 @@ void luks::loadInnerFileSystem(const QString& mapperNode)
                                                     *this);
     setLabel(m_innerFs->readLabel(mapperNode));
     setUUID(m_innerFs->readUUID(mapperNode));
-    setSectorsUsed(m_innerFs->readUsedCapacity(mapperNode)/m_logicalSectorSize);
+    if (m_innerFs->supportGetUsed() == FileSystem::cmdSupportFileSystem) // FIXME:also implement checking space if partition is mounted
+        setSectorsUsed(m_innerFs->readUsedCapacity(mapperNode)/m_logicalSectorSize);
 }
 
 void luks::createInnerFileSystem(FileSystem::Type type)
diff --git a/src/plugins/libparted/libpartedbackend.cpp b/src/plugins/libparted/libpartedbackend.cpp
index a287ce6..0e15f8b 100644
--- a/src/plugins/libparted/libpartedbackend.cpp
+++ b/src/plugins/libparted/libpartedbackend.cpp
@@ -362,7 +362,6 @@ void LibPartedBackend::scanDevicePartitions(PedDevice*, Device& d, PedDisk* pedD
 
             if (isCryptOpen) {
                 luksFs->loadInnerFileSystem(mapperNode);
-                luksFs->setSectorsUsed(luksFs->readUsedCapacity(mapperNode) / d.logicalSectorSize());
 
                 mountPoint = mountPoints.findByDevice(mapperNode) ?
                              mountPoints.findByDevice(mapperNode)->mountPoint() :