diff --git a/include/libwebsockets/lws-display.h b/include/libwebsockets/lws-display.h
index 9e4e8a2d3..6f3dbb0aa 100644
--- a/include/libwebsockets/lws-display.h
+++ b/include/libwebsockets/lws-display.h
@@ -56,6 +56,7 @@ typedef struct lws_surface_info {
 	lws_surface_type_t		type;
 	uint8_t				greyscale:1; /* line: 0 = RGBA, 1 = YA */
 	uint8_t				partial:1; /* can handle partial */
+	uint8_t				render_to_rgba:1; /* render to 32-bit RGBA, not 24-bit RGB */
 } lws_surface_info_t;
 
 typedef struct lws_greyscale_error {
diff --git a/lib/misc/dlo/dlo.c b/lib/misc/dlo/dlo.c
index de6642a7a..c67e895c3 100644
--- a/lib/misc/dlo/dlo.c
+++ b/lib/misc/dlo/dlo.c
@@ -95,7 +95,7 @@ lws_surface_set_px(const lws_surface_info_t *ic, uint8_t *line, int x,
 
 	/* line composition buffer is 24-bit RGB per pixel */
 
-	line += 3 * x;
+	line += (ic->render_to_rgba ? 4 : 3) * x;
 
 	alpha = LWSDC_ALPHA(*c);
 	ialpha = 255 - alpha;
@@ -109,7 +109,10 @@ lws_surface_set_px(const lws_surface_info_t *ic, uint8_t *line, int x,
 
 	*line++ = rgb[0];
 	*line++ = rgb[1];
-	*line = rgb[2];
+	*line++ = rgb[2];
+
+	if (ic->render_to_rgba)
+		*line = 0xff;
 }
 
 /*