diff --git a/Applications/PaintBrush/ToolboxWidget.cpp b/Applications/PaintBrush/ToolboxWidget.cpp
index 1890c8e0f3..c548755a76 100644
--- a/Applications/PaintBrush/ToolboxWidget.cpp
+++ b/Applications/PaintBrush/ToolboxWidget.cpp
@@ -63,6 +63,7 @@ public:
         });
 
         set_action(*m_action);
+        m_toolbox.m_action_group.add_action(*m_action);
     }
 
     const Tool& tool() const { return *m_tool; }
@@ -96,6 +97,9 @@ ToolboxWidget::ToolboxWidget()
     set_layout<GUI::VerticalBoxLayout>();
     layout()->set_margins({ 4, 4, 4, 4 });
 
+    m_action_group.set_exclusive(true);
+    m_action_group.set_unchecking_allowed(false);
+
     auto add_tool = [&](const StringView& name, const StringView& icon_name, const GUI::Shortcut& shortcut, NonnullOwnPtr<Tool> tool) {
         auto& button = add<ToolButton>(*this, name, shortcut, move(tool));
         button.set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
diff --git a/Applications/PaintBrush/ToolboxWidget.h b/Applications/PaintBrush/ToolboxWidget.h
index 561951742e..4f71565dc7 100644
--- a/Applications/PaintBrush/ToolboxWidget.h
+++ b/Applications/PaintBrush/ToolboxWidget.h
@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <LibGUI/ActionGroup.h>
 #include <LibGUI/Frame.h>
 
 namespace PaintBrush {
@@ -40,7 +41,11 @@ public:
     Function<void(Tool*)> on_tool_selection;
 
 private:
+    friend class ToolButton;
+
     explicit ToolboxWidget();
+
+    GUI::ActionGroup m_action_group;
 };
 
 }