diff --git a/src/finn/util/fpgadataflow.py b/src/finn/util/fpgadataflow.py
index c2725574836943ef0199d498088a1732f02c4b41..e48d26096170de0fd2657ca2c33554b6bc2e5dbd 100644
--- a/src/finn/util/fpgadataflow.py
+++ b/src/finn/util/fpgadataflow.py
@@ -51,4 +51,4 @@ def pyverilate_get_liveness_threshold_cycles():
     """Return the number of no-output cycles rtlsim will wait before assuming
     the simulation is not finishing and throwing an exception."""
 
-    return os.getenv("LIVENESS_THRESHOLD", 100)
+    return int(os.getenv("LIVENESS_THRESHOLD", 100))