diff --git a/src/main.rs b/src/main.rs
index 8b78f6b..7b3933b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -80,11 +80,11 @@ struct Cli {
     freq: u32,
     
     /// Spotter latitude DD.dddd
-    #[arg(short = 'y', long, default_value_t = -9999.0_f64)]
+    #[arg(short = 'y', long, default_value_t = -9999.0_f64, allow_negative_numbers = true)]
     my_lat: f64,
     
     /// Spotter longitude DD.dddd; to send negaitve (W or S), use = e.g. --my-lon=-97.1
-    #[arg(short = 'x', long, default_value_t = -9999.0_f64)]
+    #[arg(short = 'x', long, default_value_t = -9999.0_f64, allow_negative_numbers = true)]
     my_lon: f64,
     
 }