3 files changed, 23 insertions, 3 deletions
diff --git a/scene/gui/subviewport_container.cpp b/scene/gui/subviewport_container.cpp
index 3ad84cbc6d..8d599f074a 100644
--- a/scene/gui/subviewport_container.cpp
+++ b/scene/gui/subviewport_container.cpp
@@ -85,7 +85,7 @@ void SubViewportContainer::set_stretch_shrink(int p_shrink) {
 			continue;
 		}
 
-		c->set_size(get_size() / shrink);
+		c->set_size_force(get_size() / shrink);
 	}
 
 	queue_redraw();
@@ -116,7 +116,7 @@ void SubViewportContainer::_notification(int p_what) {
 					continue;
 				}
 
-				c->set_size(get_size() / shrink);
+				c->set_size_force(get_size() / shrink);
 			}
 		} break;
 
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 234cebd821..430725f2bf 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -4080,9 +4080,26 @@ Viewport::~Viewport() {
 /////////////////////////////////
 
 void SubViewport::set_size(const Size2i &p_size) {
-	_set_size(p_size, _get_size_2d_override(), Rect2i(), _stretch_transform(), true);
+	_internal_set_size(p_size);
+}
 
+void SubViewport::set_size_force(const Size2i &p_size) {
+	// Use only for setting the size from the parent SubViewportContainer with enabled stretch mode.
+	// Don't expose function to scripting.
+	_internal_set_size(p_size, true);
+}
+
+void SubViewport::_internal_set_size(const Size2i &p_size, bool p_force) {
 	SubViewportContainer *c = Object::cast_to<SubViewportContainer>(get_parent());
+	if (!p_force && c && c->is_stretch_enabled()) {
+#ifdef DEBUG_ENABLED
+		WARN_PRINT("Can't change the size of a `SubViewport` with a `SubViewportContainer` parent that has `stretch` enabled. Set `SubViewportContainer.stretch` to `false` to allow changing the size manually.");
+#endif // DEBUG_ENABLED
+		return;
+	}
+
+	_set_size(p_size, _get_size_2d_override(), Rect2i(), _stretch_transform(), true);
+
 	if (c) {
 		c->update_minimum_size();
 	}
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index 6f67649ea3..414b5a4adb 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -743,6 +743,8 @@ private:
 	ClearMode clear_mode = CLEAR_MODE_ALWAYS;
 	bool size_2d_override_stretch = false;
 
+	void _internal_set_size(const Size2i &p_size, bool p_force = false);
+
 protected:
 	static void _bind_methods();
 	virtual DisplayServer::WindowID get_window_id() const override;
@@ -752,6 +754,7 @@ protected:
 public:
 	void set_size(const Size2i &p_size);
 	Size2i get_size() const;
+	void set_size_force(const Size2i &p_size);
 
 	void set_size_2d_override(const Size2i &p_size);
 	Size2i get_size_2d_override() const;