diff --git a/src/mesa/state_tracker/st_cb_clear.c b/src/mesa/state_tracker/st_cb_clear.c
index 4fe6195a070..58650714398 100644
--- a/src/mesa/state_tracker/st_cb_clear.c
+++ b/src/mesa/state_tracker/st_cb_clear.c
@@ -259,7 +259,13 @@ draw_quad(GLcontext *ctx,
       verts[i][1][3] = color[3];
    }
 
-   st_draw_vertices(ctx, PIPE_PRIM_QUADS, 4, (float *) verts, 2, GL_FALSE);
+   st_draw_vertices(ctx, PIPE_PRIM_POLYGON, 4, (float *) verts, 2,
+#if TEST_DRAW_PASSTHROUGH
+                    GL_TRUE
+#else
+                    GL_FALSE
+#endif
+                    );
 }