diff --git a/vskernels/kernels/fmtconv.py b/vskernels/kernels/fmtconv.py
index 1dca4b0..b81c424 100644
--- a/vskernels/kernels/fmtconv.py
+++ b/vskernels/kernels/fmtconv.py
@@ -176,4 +176,4 @@ def kernel_radius(self) -> int:
         if taps_hv is None:
             taps_hv = self.taps
 
-        return ceil(self.taps)
+        return ceil(taps_hv)