diff --git a/src/lib.rs b/src/lib.rs
index dc4ab4f4847213231d1e94d9640cb305b0cf649e..af106ff69e796f9ec0315b6468bda5a10bea7d2a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -126,7 +126,7 @@ fn read_from_serial(mut outputs: Output<'_>, args: Args<'_>) -> SResult<()> {
     args.assert_params_max_len(2)?;
     let port = get_port_name(1, &args)?;
     // Get the number of doubles to read from the input argument
-    let arg: f32 = args
+    let arg: f64 = args
         .get(2, Error::MissingReadAmount)?
         .into_rust()
         .map_mexerr(|e| Error::InvalidReadAmount(Box::new(e)))?;