diff --git a/src/gateware/cxp_frame_pipeline.py b/src/gateware/cxp_frame_pipeline.py
index f2ddffa..08fdceb 100644
--- a/src/gateware/cxp_frame_pipeline.py
+++ b/src/gateware/cxp_frame_pipeline.py
@@ -543,7 +543,7 @@ class Pixel_Coordinate_Tracker(Module):
     """track pixel coordinates."""
     def __init__(self, res_width):
     # largest x/y pixel size supported by frame header are 24 bits
-        assert res_width == 3*char_width
+        assert res_width <= 3*char_width
 
         self.y_size = Signal(3*char_width)
         self.sink = stream.Endpoint(pixel4x_layout)