diff --git a/src/app/app.rs b/src/app/app.rs
index d26ef13..93ab620 100644
--- a/src/app/app.rs
+++ b/src/app/app.rs
@@ -18,7 +18,7 @@ use ratatui::{
 use crate::app::{
     clipboard::Clipboard,
     error_msg::StatusMessage,
-    logic::{self, calc::{Grid, get_header_size}, cell::CellType},
+    logic::{calc::{Grid, get_header_size}, cell::CellType},
     mode::Mode,
     screen::ScreenSpace,
 };
diff --git a/src/app/logic/calc.rs b/src/app/logic/calc.rs
index 851c4c7..f9d4662 100644
--- a/src/app/logic/calc.rs
+++ b/src/app/logic/calc.rs
@@ -851,6 +851,19 @@ fn parse_csv() {
     );
 }
 
+#[test]
+fn invalid_ranges() {
+    let mut grid = Grid::new();
+
+    grid.set_cell("A0", 2.);
+    grid.set_cell("A1", 1.);
+    // ASCII to number conversion needs to not overflow
+    grid.set_cell("B0", "=sum($:A)".to_string());
+
+    let cell = grid.get_cell("B0").as_ref().expect("Just set it");
+    let _ = grid.evaluate(&cell.to_string()).expect("Should evaluate.");
+}
+
 #[test]
 fn ranges() {
     let mut grid = Grid::new();
diff --git a/src/app/mode.rs b/src/app/mode.rs
index c589c60..60b1dc2 100644
--- a/src/app/mode.rs
+++ b/src/app/mode.rs
@@ -15,7 +15,7 @@ use crate::app::{
     app::App,
     error_msg::StatusMessage,
     logic::{
-        calc::{CSV_EXT, CUSTOM_EXT, Grid, LEN},
+        calc::{Grid, LEN},
         cell::CellType,
     },
 };
diff --git a/src/app/screen.rs b/src/app/screen.rs
index 90524d7..65c2651 100644
--- a/src/app/screen.rs
+++ b/src/app/screen.rs
@@ -2,7 +2,7 @@ use std::{collections::HashMap, sync::RwLock};
 
 use ratatui::prelude;
 
-use crate::app::logic::calc::{self, LEN};
+use crate::app::logic::calc::LEN;
 
 pub struct ScreenSpace {
     /// This is measured in cells.