diff --git a/test/test-suite/helpers/helpers.py b/test/test-suite/helpers/helpers.py
index 7a8b7caa..884d47b5 100644
--- a/test/test-suite/helpers/helpers.py
+++ b/test/test-suite/helpers/helpers.py
@@ -49,6 +49,7 @@ colour_colourspaces = [pyvips.Interpretation.XYZ,
                        pyvips.Interpretation.LCH,
                        pyvips.Interpretation.CMC,
                        pyvips.Interpretation.LABS,
+                       pyvips.Interpretation.CMYK,
                        pyvips.Interpretation.SCRGB,
                        pyvips.Interpretation.HSV,
                        pyvips.Interpretation.SRGB,