diff --git a/doc/classes/StyleBoxTexture.xml b/doc/classes/StyleBoxTexture.xml
index 745187ed635..f2f6e59a9e8 100644
--- a/doc/classes/StyleBoxTexture.xml
+++ b/doc/classes/StyleBoxTexture.xml
@@ -82,6 +82,7 @@
 		<member name="region_rect" type="Rect2" setter="set_region_rect" getter="get_region_rect" default="Rect2(0, 0, 0, 0)">
 			Species a sub-region of the texture to use.
 			This is equivalent to first wrapping the texture in an [AtlasTexture] with the same region.
+			If empty ([code]Rect2(0, 0, 0, 0)[/code]), the whole texture will be used.
 		</member>
 		<member name="texture" type="Texture2D" setter="set_texture" getter="get_texture">
 			The texture to use when drawing this style box.
diff --git a/editor/plugins/texture_region_editor_plugin.cpp b/editor/plugins/texture_region_editor_plugin.cpp
index 76f2bb7bb5f..c5aa60c816a 100644
--- a/editor/plugins/texture_region_editor_plugin.cpp
+++ b/editor/plugins/texture_region_editor_plugin.cpp
@@ -740,6 +740,9 @@ void TextureRegionEditor::_update_rect() {
 		}
 	} else if (obj_styleBox.is_valid()) {
 		rect = obj_styleBox->get_region_rect();
+		if (rect == Rect2()) {
+			rect = Rect2(Vector2(), obj_styleBox->get_texture()->get_size());
+		}
 	}
 }
 
diff --git a/scene/resources/style_box.cpp b/scene/resources/style_box.cpp
index 0beb62185d1..fbbe98d0227 100644
--- a/scene/resources/style_box.cpp
+++ b/scene/resources/style_box.cpp
@@ -151,11 +151,6 @@ void StyleBoxTexture::set_texture(Ref<Texture2D> p_texture) {
 		return;
 	}
 	texture = p_texture;
-	if (p_texture.is_null()) {
-		region_rect = Rect2(0, 0, 0, 0);
-	} else {
-		region_rect = Rect2(Point2(), texture->get_size());
-	}
 	emit_changed();
 }