diff --git a/src/gui/DamarisGUI.py b/src/gui/DamarisGUI.py
index 54ce07d..c5d80f4 100644
--- a/src/gui/DamarisGUI.py
+++ b/src/gui/DamarisGUI.py
@@ -2328,10 +2328,11 @@ class MonitorWidgets:
         self.display_source_combobox = self.xml_gui.get_object( "display_source_combobox" )
         self.display_source_treestore = gtk.TreeStore( gobject.TYPE_STRING )
         self.display_source_combobox.set_model( self.display_source_treestore )
-        #Cell Renderer seems to be automatically inserted in GTK3+
-        #display_source_cell = gtk.CellRendererText( )
-        #self.display_source_combobox.pack_start( display_source_cell, True )
-        #self.display_source_combobox.add_attribute( display_source_cell, 'text', 0 )
+        display_source_cell = gtk.CellRendererText( )
+        self.display_source_combobox.pack_start( display_source_cell, True )
+        self.display_source_combobox.add_attribute( display_source_cell, 'text', 0 )
+        # GTK3 fix: Prevent blank space from child tree nodes in popup
+        self.display_source_combobox.set_wrap_width(1)
         self.source_list_reset( )
         self.display_source_path_label = self.xml_gui.get_object( "display_source_path_label" )
 
diff --git a/src/gui/damaris.xml b/src/gui/damaris.xml
index 45fa134..26c7c83 100644
--- a/src/gui/damaris.xml
+++ b/src/gui/damaris.xml
@@ -1047,9 +1047,9 @@ Public License instead of this License.
                                   </packing>
                                 </child>
                                 <child>
-                                  <object class="GtkComboBoxText" id="display_source_combobox">
+                                  <object class="GtkComboBox" id="display_source_combobox">
                                     <property name="visible">True</property>
-                                    <property name="add_tearoffs">True</property>
+                                    <property name="popup-fixed-width">False</property>
                                   </object>
                                   <packing>
                                     <property name="expand">False</property>