diff --git a/sodetlib/det_config.py b/sodetlib/det_config.py
index 9950bee..a2b3114 100644
--- a/sodetlib/det_config.py
+++ b/sodetlib/det_config.py
@@ -102,7 +102,10 @@ def odict_rep(dumper, data):
     "gradientDescentConvergeHz": 500,
     "gradientDescentStepHz": 5000,
     "gradientDescentMomentum": 1,
-    "gradientDescentBeta": 0.1
+    "gradientDescentBeta": 0.1,
+
+    # Fixed tones
+    "fixed_tones": {"freq_offsets": [], "channels": [], "tone_power": 0},
 }
 bg_defaults = {
     'overbias_voltage': 19.9,