diff --git a/noptica.py b/noptica.py
index 3da4fd3..b8130bf 100644
--- a/noptica.py
+++ b/noptica.py
@@ -66,8 +66,8 @@ class Stabilizer:
         true_i, amplitude = parabolic(spectrum, i)
         freq = 0.5 * self.freq_sample * true_i / len(spectrum)
 
-        if amplitude > threshold:
-            tuning = (freq - target_freq)*k
+        if amplitude > self.amp_threshold:
+            tuning = (freq - self.freq_target)*self.k
         else:
             tuning = 0.0
         self.tuner.set(tuning)