diff --git a/libnx/nxtk/nxtk_drawlinewindow.c b/libnx/nxtk/nxtk_drawlinewindow.c
index 4c4dd49d07..a616ce1320 100644
--- a/libnx/nxtk/nxtk_drawlinewindow.c
+++ b/libnx/nxtk/nxtk_drawlinewindow.c
@@ -94,7 +94,7 @@
 
 int nxtk_drawlinewindow(NXTKWINDOW hfwnd, FAR struct nxgl_vector_s *vector,
                         nxgl_coord_t width, nxgl_mxpixel_t color[CONFIG_NX_NPLANES],
-                        bool caps)
+                        uint8_t caps)
 
 {
   struct nxgl_trapezoid_s trap[3];