diff --git a/libs/ui/tool/kis_tool_paint.cc b/libs/ui/tool/kis_tool_paint.cc
--- a/libs/ui/tool/kis_tool_paint.cc
+++ b/libs/ui/tool/kis_tool_paint.cc
@@ -172,8 +172,10 @@
 {
     if (currentPaintOpPreset()) emit statusTextChanged(currentPaintOpPreset()->name());
     KisTool::activate(toolActivation, shapes);
-    connect(action("increase_brush_size"), SIGNAL(triggered()), SLOT(increaseBrushSize()), Qt::UniqueConnection);
-    connect(action("decrease_brush_size"), SIGNAL(triggered()), SLOT(decreaseBrushSize()), Qt::UniqueConnection);
+    if (flags() & KisTool::FLAG_USES_CUSTOM_SIZE) {
+        connect(action("increase_brush_size"), SIGNAL(triggered()), SLOT(increaseBrushSize()), Qt::UniqueConnection);
+        connect(action("decrease_brush_size"), SIGNAL(triggered()), SLOT(decreaseBrushSize()), Qt::UniqueConnection);
+    }
 
     KisCanvasResourceProvider *provider = qobject_cast<KisCanvas2*>(canvas())->viewManager()->resourceProvider();
     m_oldOpacity = provider->opacity();
@@ -182,9 +184,10 @@
 
 void KisToolPaint::deactivate()
 {
-
-    disconnect(action("increase_brush_size"), 0, this, 0);
-    disconnect(action("decrease_brush_size"), 0, this, 0);
+    if (flags() & KisTool::FLAG_USES_CUSTOM_SIZE) {
+        disconnect(action("increase_brush_size"), 0, this, 0);
+        disconnect(action("decrease_brush_size"), 0, this, 0);
+    }
 
     KisCanvasResourceProvider *provider = qobject_cast<KisCanvas2*>(canvas())->viewManager()->resourceProvider();
     m_localOpacity = provider->opacity();