diff --git a/src/core/partitiontable.cpp b/src/core/partitiontable.cpp
index b54be1a..9f92120 100644
--- a/src/core/partitiontable.cpp
+++ b/src/core/partitiontable.cpp
@@ -372,7 +372,7 @@ void PartitionTable::removeUnallocated()
     @param p the parent PartitionNode (may be this or an extended Partition)
     @param start the first sector to begin looking for free space
 */
-void PartitionTable::insertUnallocated(const Device& d, PartitionNode* p, qint64 start) const
+void PartitionTable::insertUnallocated(const Device& d, PartitionNode* p, qint64 start)
 {
     Q_ASSERT(p);
 
@@ -381,6 +381,7 @@ void PartitionTable::insertUnallocated(const Device& d, PartitionNode* p, qint64
     if (d.type() == Device::LVM_Device && !p->children().isEmpty()) {
         // rearranging the sectors of all partitions to keep unallocated space at the end
         lastEnd = 0;
+        qSort(children().begin(), children().end(), [](const Partition* p1, const Partition* p2) { return p1->deviceNode() < p2->deviceNode(); });
         for (const auto &child : children()) {
             qint64 totalSectors = child->length();
             child->setFirstSector(lastEnd);
diff --git a/src/core/partitiontable.h b/src/core/partitiontable.h
index 929fd8e..253cc44 100644
--- a/src/core/partitiontable.h
+++ b/src/core/partitiontable.h
@@ -161,7 +161,7 @@ public:
     }
 
     void updateUnallocated(const Device& d);
-    void insertUnallocated(const Device& d, PartitionNode* p, qint64 start) const;
+    void insertUnallocated(const Device& d, PartitionNode* p, qint64 start);
 
     bool isSectorBased(const Device& d) const;