diff --git a/src/display/side_by_side.rs b/src/display/side_by_side.rs
index df360b584f..f7d31825ef 100644
--- a/src/display/side_by_side.rs
+++ b/src/display/side_by_side.rs
@@ -18,7 +18,7 @@ use crate::{
         BackgroundColor,
     },
     hash::DftHashMap,
-    lines::{codepoint_len, format_line_num},
+    lines::format_line_num,
     options::{DisplayMode, DisplayOptions},
     parse::syntax::{zip_pad_shorter, MatchedPos},
     summary::FileFormat,
@@ -166,31 +166,16 @@ struct SourceDimensions {
 }
 
 impl SourceDimensions {
-    fn new(
-        terminal_width: usize,
-        line_nums: &[(Option<LineNumber>, Option<LineNumber>)],
-        lhs_lines: &[&str],
-        rhs_lines: &[&str],
-    ) -> Self {
+    fn new(terminal_width: usize, line_nums: &[(Option<LineNumber>, Option<LineNumber>)]) -> Self {
         let mut lhs_max_line: LineNumber = 1.into();
         let mut rhs_max_line: LineNumber = 1.into();
-        let mut lhs_max_content = 1;
-        let mut rhs_max_content = 1;
 
         for (lhs_line_num, rhs_line_num) in line_nums {
             if let Some(lhs_line_num) = lhs_line_num {
                 lhs_max_line = max(lhs_max_line, *lhs_line_num);
-                lhs_max_content = max(
-                    lhs_max_content,
-                    codepoint_len(lhs_lines[lhs_line_num.as_usize()]),
-                );
             }
             if let Some(rhs_line_num) = rhs_line_num {
                 rhs_max_line = max(rhs_max_line, *rhs_line_num);
-                rhs_max_content = max(
-                    rhs_max_content,
-                    codepoint_len(rhs_lines[rhs_line_num.as_usize()]),
-                );
             }
         }
 
@@ -436,12 +421,7 @@ pub(crate) fn print(
         let no_rhs_changes = hunk.novel_rhs.is_empty();
         let same_lines = aligned_lines.iter().all(|(l, r)| l == r);
 
-        let source_dims = SourceDimensions::new(
-            display_options.display_width,
-            aligned_lines,
-            &lhs_lines,
-            &rhs_lines,
-        );
+        let source_dims = SourceDimensions::new(display_options.display_width, aligned_lines);
         for (lhs_line_num, rhs_line_num) in aligned_lines {
             let lhs_line_novel = highlight_as_novel(
                 *lhs_line_num,
@@ -606,14 +586,7 @@ mod tests {
     #[test]
     fn test_width_calculations() {
         let line_nums = [(Some(1.into()), Some(10.into()))];
-        let source_dims = SourceDimensions::new(
-            80,
-            &line_nums,
-            &"foo\nbar\n".lines().collect::<Vec<_>>(),
-            &"x\nx\nx\nx\nx\nx\nx\nx\nx\nx\nx\n"
-                .lines()
-                .collect::<Vec<_>>(),
-        );
+        let source_dims = SourceDimensions::new(80, &line_nums);
 
         assert_eq!(source_dims.lhs_line_nums_width, 2);
         assert_eq!(source_dims.rhs_line_nums_width, 3);
@@ -627,8 +600,6 @@ mod tests {
                 (Some(0.into()), Some(0.into())),
                 (Some(1.into()), Some(1.into())),
             ],
-            &"foo\nbar\n".lines().collect::<Vec<_>>(),
-            &"fox\nbax\n".lines().collect::<Vec<_>>(),
         );
 
         assert_eq!(
@@ -649,8 +620,6 @@ mod tests {
                 (Some(0.into()), Some(0.into())),
                 (Some(1.into()), Some(1.into())),
             ],
-            &"foo\nbar\n".lines().collect::<Vec<_>>(),
-            &"fox\nbax\n".lines().collect::<Vec<_>>(),
         );
 
         assert_eq!(
diff --git a/src/lines.rs b/src/lines.rs
index 3589121296..a47182cd6e 100644
--- a/src/lines.rs
+++ b/src/lines.rs
@@ -16,12 +16,6 @@ struct LinePosition {
     column: usize,
 }
 
-/// Return the length of `s` in codepoints. This is important when
-/// finding character boundaries for slicing without errors.
-pub(crate) fn codepoint_len(s: &str) -> usize {
-    s.chars().count()
-}
-
 /// Return the length of `s` in bytes.
 ///
 /// This is a trivial wrapper to make it clear when we want bytes not
@@ -80,11 +74,6 @@ mod tests {
         assert_eq!(line.max_line().0, 1);
     }
 
-    #[test]
-    fn codepoint_len_non_ascii() {
-        assert_eq!(codepoint_len("ƒoo"), 3);
-    }
-
     #[test]
     fn test_is_all_whiteapce() {
         assert!(is_all_whitespace(" \n\t"));