diff --git a/src/finn/transformation/fpgadataflow/derive_characteristic.py b/src/finn/transformation/fpgadataflow/derive_characteristic.py
index 474cd10d847675d5aa633a047c3e80ff16418ba3..0a32ba7e73d81c794dd39be382f5dcdec5fe71a9 100644
--- a/src/finn/transformation/fpgadataflow/derive_characteristic.py
+++ b/src/finn/transformation/fpgadataflow/derive_characteristic.py
@@ -89,7 +89,7 @@ class DeriveCharacteristic(NodeLocalTransformation):
                     # try to come up with an optimistic estimate
                     exp_cycles = min(n_inps, n_outs)
                 assert (
-                    exp_cycles < self.period
+                    exp_cycles <= self.period
                 ), "Period %d too short to characterize %s : expects min %d cycles" % (
                     self.period,
                     node.name,