diff --git a/ChangeLog.txt b/ChangeLog.txt
index 89f4b9919..7e9f18f8e 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -33,6 +33,7 @@
 - [#978] Don't show errors in History dialog.
 - Fixed translation numbers in scientific notation.
 - Fix dialog for tool Point along perpendicular. No memory of line color settings. 
+- Fix crash after uniting three pieces in sequence.
 
 # Version 0.6.1 October 23, 2018
 - [#885] Regression. Broken support for multi size measurements.
diff --git a/src/libs/vtools/tools/vtooluniondetails.cpp b/src/libs/vtools/tools/vtooluniondetails.cpp
index 3ae47fa0f..b7e91afb8 100644
--- a/src/libs/vtools/tools/vtooluniondetails.cpp
+++ b/src/libs/vtools/tools/vtooluniondetails.cpp
@@ -413,6 +413,7 @@ quint32 AddNodePoint(const VPieceNode &node, const VToolUnionDetailsInitData &in
 
     const quint32 idObject = initData.data->AddGObject(point.take());
     children.append(idObject);
+    point1->setIdObject(idObject);
     point1->setMode(Draw::Modeling);
     const quint32 id = initData.data->AddGObject(point1.take());
 
@@ -540,6 +541,7 @@ quint32 AddNodeArc(const VPieceNode &node, const VToolUnionDetailsInitData &init
     const quint32 idObject = initData.data->AddGObject(arc1.take());
     children.append(idObject);
 
+    arc2->setIdObject(idObject);
     arc2->setMode(Draw::Modeling);
     const quint32 id = initData.data->AddGObject(arc2.take());
 
@@ -593,6 +595,7 @@ quint32 AddNodeElArc(const VPieceNode &node, const VToolUnionDetailsInitData &in
     const quint32 idObject = initData.data->AddGObject(arc1.take());
     children.append(idObject);
 
+    arc2->setIdObject(idObject);
     arc2->setMode(Draw::Modeling);
     const quint32 id = initData.data->AddGObject(arc2.take());
 
@@ -638,6 +641,7 @@ quint32 AddNodeSpline(const VPieceNode &node, const VToolUnionDetailsInitData &i
     children.append(idObject);
 
     VSpline *spl1 = new VSpline(*spl);
+    spl1->setIdObject(idObject);
     spl1->setMode(Draw::Modeling);
     const quint32 id = initData.data->AddGObject(spl1);
 
@@ -711,6 +715,7 @@ quint32 AddNodeSplinePath(const VPieceNode &node, const VToolUnionDetailsInitDat
     const quint32 idObject = initData.data->AddGObject(path.take());
     children.append(idObject);
 
+    path1->setIdObject(idObject);
     path1->setMode(Draw::Modeling);
     const quint32 id = initData.data->AddGObject(path1.take());