diff --git a/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp b/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
index 0fe1c42c63..3b08693b65 100644
--- a/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
+++ b/src/Mod/Sketcher/Gui/CommandSketcherTools.cpp
@@ -832,6 +832,12 @@ void CmdSketcherSymmetry::activated(int iMsg)
 
     // get the needed lists and objects
     const std::vector<std::string> &SubNames = selection[0].getSubNames();
+    if (SubNames.empty()) {
+        QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
+            QObject::tr("Select elements from a single sketch."));
+        return;
+    }
+
     Sketcher::SketchObject* Obj = static_cast<Sketcher::SketchObject*>(selection[0].getObject());
 
     getSelection().clearSelection();
@@ -1620,6 +1626,12 @@ void CmdSketcherRectangularArray::activated(int iMsg)
     
     // get the needed lists and objects
     const std::vector<std::string> &SubNames = selection[0].getSubNames();
+    if (SubNames.empty()) {
+        QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
+            QObject::tr("Select elements from a single sketch."));
+        return;
+    }
+
     Sketcher::SketchObject* Obj = static_cast<Sketcher::SketchObject*>(selection[0].getObject());
     
     getSelection().clearSelection();