diff --git a/include/types/wlr_xdg_shell.h b/include/types/wlr_xdg_shell.h
index 34dec2adb..12c392a19 100644
--- a/include/types/wlr_xdg_shell.h
+++ b/include/types/wlr_xdg_shell.h
@@ -36,4 +36,9 @@ struct wlr_xdg_toplevel_configure *send_xdg_toplevel_configure(
 void handle_xdg_toplevel_ack_configure(struct wlr_xdg_toplevel *toplevel,
 	struct wlr_xdg_toplevel_configure *configure);
 
+/**
+ * Returns true if a positioner is complete.
+ */
+bool wlr_xdg_positioner_is_complete(struct wlr_xdg_positioner *positioner);
+
 #endif
diff --git a/types/xdg_shell/wlr_xdg_popup.c b/types/xdg_shell/wlr_xdg_popup.c
index 07d8d4c7d..c3bc71945 100644
--- a/types/xdg_shell/wlr_xdg_popup.c
+++ b/types/xdg_shell/wlr_xdg_popup.c
@@ -323,8 +323,13 @@ static void xdg_popup_handle_reposition(
 		return;
 	}
 
-	struct wlr_xdg_positioner *positioner =
-		wlr_xdg_positioner_from_resource(positioner_resource);
+	struct wlr_xdg_positioner *positioner = wlr_xdg_positioner_from_resource(positioner_resource);
+	if (!wlr_xdg_positioner_is_complete(positioner)) {
+		wl_resource_post_error(popup->base->client->resource,
+			XDG_WM_BASE_ERROR_INVALID_POSITIONER, "positioner object is not complete");
+		return;
+	}
+
 	wlr_xdg_positioner_rules_get_geometry(
 		&positioner->rules, &popup->scheduled.geometry);
 	popup->scheduled.rules = positioner->rules;
@@ -367,14 +372,11 @@ static void xdg_popup_handle_resource_destroy(struct wl_resource *resource) {
 	wlr_xdg_popup_destroy(popup);
 }
 
-void create_xdg_popup(struct wlr_xdg_surface *surface,
-		struct wlr_xdg_surface *parent,
+void create_xdg_popup(struct wlr_xdg_surface *surface, struct wlr_xdg_surface *parent,
 		struct wlr_xdg_positioner *positioner, uint32_t id) {
-	if (positioner->rules.size.width == 0 ||
-			positioner->rules.anchor_rect.width == 0) {
+	if (!wlr_xdg_positioner_is_complete(positioner)) {
 		wl_resource_post_error(surface->client->resource,
-			XDG_WM_BASE_ERROR_INVALID_POSITIONER,
-			"positioner object is not complete");
+			XDG_WM_BASE_ERROR_INVALID_POSITIONER, "positioner object is not complete");
 		return;
 	}
 
diff --git a/types/xdg_shell/wlr_xdg_positioner.c b/types/xdg_shell/wlr_xdg_positioner.c
index 6a991bbac..380c11310 100644
--- a/types/xdg_shell/wlr_xdg_positioner.c
+++ b/types/xdg_shell/wlr_xdg_positioner.c
@@ -203,6 +203,11 @@ static uint32_t xdg_positioner_gravity_to_wlr_edges(
 	return xdg_positioner_anchor_to_wlr_edges((enum xdg_positioner_anchor)gravity);
 }
 
+bool wlr_xdg_positioner_is_complete(struct wlr_xdg_positioner *positioner) {
+	struct wlr_xdg_positioner_rules *rules = &positioner->rules;
+	return rules->size.width > 0 && rules->anchor_rect.width > 0;
+}
+
 void wlr_xdg_positioner_rules_get_geometry(
 		const struct wlr_xdg_positioner_rules *rules, struct wlr_box *box) {
 	box->x = rules->offset.x;