diff --git a/src/core/lvmdevice.cpp b/src/core/lvmdevice.cpp
index d6b4a24..9ac375a 100644
--- a/src/core/lvmdevice.cpp
+++ b/src/core/lvmdevice.cpp
@@ -548,6 +548,7 @@ qint64 LvmDevice::freePE() const
 void LvmDevice::setFreePE(qint64 freePE) const
 {
     d_ptr->m_freePE = freePE;
+    d_ptr->m_allocPE = d_ptr->m_totalPE - freePE;
 }
 
 QString LvmDevice::UUID() const