1 files changed, 3 insertions, 2 deletions

diff --git a/src/parsing/equalizer_apo.lalrpop b/src/parsing/equalizer_apo.lalrpop
index 8003be7..3239036 100644
--- a/src/parsing/equalizer_apo.lalrpop
+++ b/src/parsing/equalizer_apo.lalrpop
@@ -5,8 +5,9 @@ use std::str::FromStr;
 grammar;
 
 pub Main: Filter = {
-    <preamp: Preamp> <eq: Eq> => Filter { preamp, frequencies: eq.0, coefficients: eq.1 }
-
+    <preamp: Preamp?> <eq: Eq> => {
+        Filter { preamp: preamp.unwrap_or(0.0), frequencies: eq.0, coefficients: eq.1 }
+    }
 }
 
 Preamp: f64 = {