diff --git a/clippy_lints/src/literal_representation.rs b/clippy_lints/src/literal_representation.rs
index dacfd7c8983b..e5d855c10aa8 100644
--- a/clippy_lints/src/literal_representation.rs
+++ b/clippy_lints/src/literal_representation.rs
@@ -193,18 +193,19 @@ impl<'a> DigitInfo<'a> {
                 self.suffix.unwrap_or("")
             )
         } else {
-            let mut hint = self.digits
+            let filtered_digits_vec = self.digits
                 .chars()
-                .rev()
                 .filter(|&c| c != '_')
-                .collect::<Vec<_>>()
+                .rev()
+                .collect::<Vec<_>>();
+            let mut hint = filtered_digits_vec
                 .chunks(group_size)
                 .map(|chunk| chunk.into_iter().rev().collect())
                 .rev()
                 .collect::<Vec<String>>()
                 .join("_");
             // Forces hexadecimal values to be grouped by 4 being filled with zeroes (e.g 0x00ab_cdef)
-            let nb_digits_to_fill = self.digits.chars().filter(|&c| c != '_').collect::<Vec<_>>().len() % 4;
+            let nb_digits_to_fill = filtered_digits_vec.len() % 4;
             if self.radix == Radix::Hexadecimal && nb_digits_to_fill != 0 {
                 hint = format!("{:0>4}{}", &hint[..nb_digits_to_fill], &hint[nb_digits_to_fill..]);
             }