diff --git a/src/ssd/ssd-border.c b/src/ssd/ssd-border.c
index 435119e2..e96c65c6 100644
--- a/src/ssd/ssd-border.c
+++ b/src/ssd/ssd-border.c
@@ -49,7 +49,7 @@ ssd_border_create(struct ssd *ssd)
 		add_scene_rect(&subtree->parts, LAB_SSD_PART_BOTTOM, parent,
 			full_width, theme->border_width, 0, height, color);
 		add_scene_rect(&subtree->parts, LAB_SSD_PART_TOP, parent,
-			width - 2 * corner_width, theme->border_width,
+			MAX(width - 2 * corner_width, 0), theme->border_width,
 			theme->border_width + corner_width,
 			-(ssd->titlebar.height + theme->border_width), color);
 	} FOR_EACH_END
@@ -123,7 +123,7 @@ ssd_border_update(struct ssd *ssd)
 		: 0;
 	int top_width = ssd->titlebar.height <= 0 || ssd->state.was_squared
 		? full_width
-		: width - 2 * corner_width;
+		: MAX(width - 2 * corner_width, 0);
 	int top_x = ssd->titlebar.height <= 0 || ssd->state.was_squared
 		? 0
 		: theme->border_width + corner_width;
diff --git a/src/ssd/ssd-part.c b/src/ssd/ssd-part.c
index 28bd130c..dbfa58f0 100644
--- a/src/ssd/ssd-part.c
+++ b/src/ssd/ssd-part.c
@@ -55,15 +55,7 @@ add_scene_rect(struct wl_list *list, enum ssd_part_type type,
 	struct wlr_scene_tree *parent, int width, int height,
 	int x, int y, float color[4])
 {
-	/*
-	 * When initialized without surface being mapped,
-	 * size may be negative. Just set to 0, next call
-	 * to ssd_*_update() will update the rect to use
-	 * its correct size.
-	 */
-	width = width >= 0 ? width : 0;
-	height = height >= 0 ? height : 0;
-
+	assert(width >= 0 && height >= 0);
 	struct ssd_part *part = add_scene_part(list, type);
 	part->node = &wlr_scene_rect_create(
 		parent, width, height, color)->node;
diff --git a/src/ssd/ssd-shadow.c b/src/ssd/ssd-shadow.c
index a1c10420..0559628c 100644
--- a/src/ssd/ssd-shadow.c
+++ b/src/ssd/ssd-shadow.c
@@ -32,8 +32,8 @@ static void
 corner_scale_crop(struct wlr_scene_buffer *buffer, int horizontal_overlap,
 		int vertical_overlap, int corner_size)
 {
-	int width = corner_size - horizontal_overlap;
-	int height = corner_size - vertical_overlap;
+	int width = MAX(corner_size - horizontal_overlap, 0);
+	int height = MAX(corner_size - vertical_overlap, 0);
 	struct wlr_fbox src_box = {
 		.x = horizontal_overlap,
 		.y = vertical_overlap,
@@ -127,7 +127,7 @@ set_shadow_part_geometry(struct ssd_part *part, int width, int height,
 		y = -titlebar_height + inset;
 		wlr_scene_node_set_position(part->node, x, y);
 		wlr_scene_buffer_set_dest_size(
-			scene_buf, visible_shadow_width, height - 2 * inset);
+			scene_buf, visible_shadow_width, MAX(height - 2 * inset, 0));
 		wlr_scene_node_set_enabled(part->node, show_sides);
 		break;
 	case LAB_SSD_PART_BOTTOM:
@@ -135,7 +135,7 @@ set_shadow_part_geometry(struct ssd_part *part, int width, int height,
 		y = -titlebar_height + height;
 		wlr_scene_node_set_position(part->node, x, y);
 		wlr_scene_buffer_set_dest_size(
-			scene_buf, width - 2 * inset, visible_shadow_width);
+			scene_buf, MAX(width - 2 * inset, 0), visible_shadow_width);
 		wlr_scene_node_set_enabled(part->node, show_topbottom);
 		break;
 	case LAB_SSD_PART_LEFT:
@@ -143,7 +143,7 @@ set_shadow_part_geometry(struct ssd_part *part, int width, int height,
 		y = -titlebar_height + inset;
 		wlr_scene_node_set_position(part->node, x, y);
 		wlr_scene_buffer_set_dest_size(
-			scene_buf, visible_shadow_width, height - 2 * inset);
+			scene_buf, visible_shadow_width, MAX(height - 2 * inset, 0));
 		wlr_scene_node_set_enabled(part->node, show_sides);
 		break;
 	case LAB_SSD_PART_TOP:
@@ -151,7 +151,7 @@ set_shadow_part_geometry(struct ssd_part *part, int width, int height,
 		y = -titlebar_height - visible_shadow_width;
 		wlr_scene_node_set_position(part->node, x, y);
 		wlr_scene_buffer_set_dest_size(
-			scene_buf, width - 2 * inset, visible_shadow_width);
+			scene_buf, MAX(width - 2 * inset, 0), visible_shadow_width);
 		wlr_scene_node_set_enabled(part->node, show_topbottom);
 		break;
 	default:
diff --git a/src/ssd/ssd-titlebar.c b/src/ssd/ssd-titlebar.c
index bd0b66e6..47cca7a2 100644
--- a/src/ssd/ssd-titlebar.c
+++ b/src/ssd/ssd-titlebar.c
@@ -58,7 +58,7 @@ ssd_titlebar_create(struct ssd *ssd)
 
 		/* Background */
 		add_scene_rect(&subtree->parts, LAB_SSD_PART_TITLEBAR, parent,
-			width - corner_width * 2, theme->titlebar_height,
+			MAX(width - corner_width * 2, 0), theme->titlebar_height,
 			corner_width, 0, color);
 		add_scene_buffer(&subtree->parts, LAB_SSD_PART_TITLEBAR_CORNER_LEFT, parent,
 			corner_top_left, -rc.theme->border_width, -rc.theme->border_width);
@@ -153,7 +153,7 @@ set_squared_corners(struct ssd *ssd, bool enable)
 		part = ssd_get_part(&subtree->parts, LAB_SSD_PART_TITLEBAR);
 		wlr_scene_node_set_position(part->node, x, 0);
 		wlr_scene_rect_set_size(wlr_scene_rect_from_node(part->node),
-			width - 2 * x, theme->titlebar_height);
+			MAX(width - 2 * x, 0), theme->titlebar_height);
 
 		part = ssd_get_part(&subtree->parts, LAB_SSD_PART_TITLEBAR_CORNER_LEFT);
 		wlr_scene_node_set_enabled(part->node, !enable);
@@ -204,9 +204,10 @@ static void
 update_visible_buttons(struct ssd *ssd)
 {
 	struct view *view = ssd->view;
-	int width = view->current.width - (2 * view->server->theme->window_titlebar_padding_width);
-	int button_width = view->server->theme->window_button_width;
-	int button_spacing = view->server->theme->window_button_spacing;
+	struct theme *theme = view->server->theme;
+	int width = MAX(view->current.width - 2 * theme->window_titlebar_padding_width, 0);
+	int button_width = theme->window_button_width;
+	int button_spacing = theme->window_button_spacing;
 	int button_count_left = wl_list_length(&rc.title_buttons_left);
 	int button_count_right = wl_list_length(&rc.title_buttons_right);
 
@@ -301,7 +302,7 @@ ssd_titlebar_update(struct ssd *ssd)
 		part = ssd_get_part(&subtree->parts, LAB_SSD_PART_TITLEBAR);
 		wlr_scene_rect_set_size(
 			wlr_scene_rect_from_node(part->node),
-			width - bg_offset * 2, theme->titlebar_height);
+			MAX(width - bg_offset * 2, 0), theme->titlebar_height);
 
 		x = theme->window_titlebar_padding_width;
 		wl_list_for_each(b, &rc.title_buttons_left, link) {