diff --git a/Changes.md b/Changes.md
index 9b969194603..9825fcdcf67 100644
--- a/Changes.md
+++ b/Changes.md
@@ -1,7 +1,11 @@
 1.4.15.x (relative to 1.4.15.1)
 ========
 
+Fixes
+-----
 
+- PathFilter : Fixed bug allowing dropping paths onto read-only `PathFilter` nodes in the graph.
+- VectorDataWidget : Fixed bug allowing dropping paths onto read-only widgets.
 
 1.4.15.1 (relative to 1.4.15.0)
 ========
diff --git a/python/GafferSceneUI/PathFilterUI.py b/python/GafferSceneUI/PathFilterUI.py
index 7ade786a71e..5811eddde44 100644
--- a/python/GafferSceneUI/PathFilterUI.py
+++ b/python/GafferSceneUI/PathFilterUI.py
@@ -236,7 +236,7 @@ def __popupMenu( menuDefinition, plugValueWidget ) :
 GafferUI.Pointer.registerPointer( "removeObjects", GafferUI.Pointer( "removeObjects.png", imath.V2i( 53, 14 ) ) )
 GafferUI.Pointer.registerPointer( "replaceObjects", GafferUI.Pointer( "replaceObjects.png", imath.V2i( 53, 14 ) ) )
 
-__DropMode = enum.Enum( "__DropMode", [ "None_", "Add", "Remove", "Replace" ] )
+__DropMode = enum.Enum( "__DropMode", [ "None_", "Add", "Remove", "Replace", "NotEditable" ] )
 
 __originalDragPointer = None
 
@@ -255,9 +255,14 @@ def __filterPlug( node ) :
 		return filterPlugs[0]
 	return None
 
+def __editable( plug ) :
+
+	return not Gaffer.MetadataAlgo.readOnly( plug ) and plug.settable()
+
 def __dropMode( nodeGadget, event ) :
 
-	if __pathsPlug( nodeGadget.node() ) is None :
+	pathsPlug = __pathsPlug( nodeGadget.node() )
+	if pathsPlug is None :
 		filter = None
 
 		filterPlug = __filterPlug( nodeGadget.node() )
@@ -267,9 +272,13 @@ def __dropMode( nodeGadget, event ) :
 		if filterPlug.getInput() is not None :
 			filter = filterPlug.source().node()
 		if filter is None :
-			return __DropMode.Replace
+			return __DropMode.Replace if __editable( filterPlug ) else __DropMode.NotEditable
 		elif not isinstance( filter, GafferScene.PathFilter ) :
 			return __DropMode.None_
+		pathsPlug = __pathsPlug( filter )
+
+	if not __editable( pathsPlug ) :
+		return __DropMode.NotEditable
 
 	if event.modifiers & event.Modifiers.Shift :
 		return __DropMode.Add
@@ -342,7 +351,10 @@ def __dragMove( nodeGadget, event ) :
 	if __originalDragPointer is None :
 		return False
 
-	GafferUI.Pointer.setCurrent( __dropMode( nodeGadget, event ).name.lower() + "Objects" )
+	dropMode = __dropMode( nodeGadget, event )
+	GafferUI.Pointer.setCurrent(
+		dropMode.name.lower() + "Objects" if dropMode != __DropMode.NotEditable else "notEditable"
+	)
 
 	return True
 
@@ -352,6 +364,9 @@ def __drop( nodeGadget, event ) :
 	if __originalDragPointer is None :
 		return False
 
+	if __dropMode( nodeGadget, event ) == __DropMode.NotEditable :
+		return True
+
 	pathsPlug = __pathsPlug( nodeGadget.node() )
 	if pathsPlug is None :
 		pathsPlug = __pathsPlug( __filterPlug( nodeGadget.node() ).source().node() )
diff --git a/python/GafferSceneUI/SetFilterUI.py b/python/GafferSceneUI/SetFilterUI.py
index 742f5363ae6..95d57d12818 100644
--- a/python/GafferSceneUI/SetFilterUI.py
+++ b/python/GafferSceneUI/SetFilterUI.py
@@ -111,7 +111,7 @@
 GafferUI.Pointer.registerPointer( "removeSets", GafferUI.Pointer( "pointerRemoveSets.png", imath.V2i( 53, 14 ) ) )
 GafferUI.Pointer.registerPointer( "replaceSets", GafferUI.Pointer( "pointerReplaceSets.png", imath.V2i( 53, 14 ) ) )
 
-__DropMode = enum.Enum( "__DropMode", [ "None_", "Add", "Remove", "Replace" ] )
+__DropMode = enum.Enum( "__DropMode", [ "None_", "Add", "Remove", "Replace", "NotEditable" ] )
 
 __originalDragPointer = None
 
@@ -146,13 +146,13 @@ def __dropMode( nodeGadget, event ) :
 		if nodeGadget.node()["filter"].getInput() is not None :
 			filter = nodeGadget.node()["filter"].source().node()
 		if filter is None :
-			return __DropMode.Replace if __editable( nodeGadget.node()["filter"] ) else __DropMode.None_
+			return __DropMode.Replace if __editable( nodeGadget.node()["filter"] ) else __DropMode.NotEditable
 		elif not isinstance( filter, GafferScene.SetFilter ) :
 			return __DropMode.None_
 		setsPlug = filter["setExpression"]
 
 	if not __editable( setsPlug ) :
-		return __DropMode.None_
+		return __DropMode.NotEditable
 
 	if event.modifiers & event.Modifiers.Shift :
 		return __DropMode.Add
@@ -201,7 +201,10 @@ def __dragMove( nodeGadget, event ) :
 	if __originalDragPointer is None :
 		return False
 
-	GafferUI.Pointer.setCurrent( __dropMode( nodeGadget, event ).name.lower() + "Sets" )
+	dropMode = __dropMode( nodeGadget, event )
+	GafferUI.Pointer.setCurrent(
+		dropMode.name.lower() + "Sets" if dropMode != __DropMode.NotEditable else "notEditable"
+	)
 
 	return True
 
@@ -211,6 +214,9 @@ def __drop( nodeGadget, event ) :
 	if __originalDragPointer is None :
 		return False
 
+	if __dropMode( nodeGadget, event ) == __DropMode.NotEditable :
+		return True
+
 	setsPlug = __setsPlug( nodeGadget.node() )
 	if setsPlug is None :
 		setsPlug = __setsPlug( nodeGadget.node()["filter"].source().node() )
diff --git a/python/GafferUI/VectorDataWidget.py b/python/GafferUI/VectorDataWidget.py
index da097cc5e85..483eed8f55e 100644
--- a/python/GafferUI/VectorDataWidget.py
+++ b/python/GafferUI/VectorDataWidget.py
@@ -621,6 +621,9 @@ def __addRows( self, button ) :
 
 	def __dragEnter( self, widget, event ) :
 
+		if not self.getEditable() :
+			return False
+
 		if event.sourceWidget is self.__tableViewHolder and widget is not self.__buttonRow[1]:
 			# we don't accept drags from ourself unless the target is the remove button
 			return False