diff --git a/src/finn/core/data_layout.py b/src/finn/core/data_layout.py
index 75751fcc71bb32a67cf47069b96b3f035ecb8d61..3971d221527d3862346c06cf415831c27e5cba8b 100644
--- a/src/finn/core/data_layout.py
+++ b/src/finn/core/data_layout.py
@@ -32,3 +32,4 @@
 NHWC = ["N", "H", "W", "C"]
 NCHW = ["N", "C", "H", "W"]
 NC = ["N", "C"]
+UNKNOWN = []