diff --git a/test/decoder.py b/test/decoder.py
index 388fc62..4dd8486 100644
--- a/test/decoder.py
+++ b/test/decoder.py
@@ -81,7 +81,7 @@ def synthesize(self, x, bw, pitch, nbytes):
         x = np.append(x, np.zeros(self.ns - self.ne))
         x = self.mdct.run(x)
 
-        x = self.ltpf.run(x, len(data))
+        x = self.ltpf.run(x)
 
         return x