diff --git a/clippy_lints/src/literal_representation.rs b/clippy_lints/src/literal_representation.rs
index 8b8d7903f..c534ef327 100644
--- a/clippy_lints/src/literal_representation.rs
+++ b/clippy_lints/src/literal_representation.rs
@@ -375,7 +375,7 @@ impl LiteralDigitGrouping {
 
         if underscore_positions.is_empty() {
             // Check if literal needs underscores.
-            if digits.len() > 4 {
+            if digits.len() > 5 {
                 Err(WarningType::UnreadableLiteral)
             } else {
                 Ok(0)
diff --git a/tests/ui/unreadable_literal.rs b/tests/ui/unreadable_literal.rs
index 94b53f80b..0ec757cfb 100644
--- a/tests/ui/unreadable_literal.rs
+++ b/tests/ui/unreadable_literal.rs
@@ -3,8 +3,8 @@
 #[warn(unreadable_literal)]
 #[allow(unused_variables)]
 fn main() {
-    let good = (0b1011_i64, 0o1_234_u32, 0x1_234_567, 1_2345_6789, 1234_f32, 1_234.12_f32, 1_234.123_f32, 1.123_4_f32);
-    let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
+    let good = (0b1011_i64, 0o1_234_u32, 0x1_234_567, 65536, 1_2345_6789, 1234_f32, 1_234.12_f32, 1_234.123_f32, 1.123_4_f32);
+    let bad = (0b110110_i64, 0x12345678901_usize, 123456_f32, 1.234567_f32);
     let good_sci = 1.1234e1;
-    let bad_sci = 1.12345e1;
+    let bad_sci = 1.123456e1;
 }
diff --git a/tests/ui/unreadable_literal.stderr b/tests/ui/unreadable_literal.stderr
index b16a58ec2..4b78e2e12 100644
--- a/tests/ui/unreadable_literal.stderr
+++ b/tests/ui/unreadable_literal.stderr
@@ -1,34 +1,34 @@
 error: long literal lacking separators
  --> $DIR/unreadable_literal.rs:7:16
   |
-7 |     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
-  |                ^^^^^^^^^^^ help: consider: `0b1_0110_i64`
+7 |     let bad = (0b110110_i64, 0x12345678901_usize, 123456_f32, 1.234567_f32);
+  |                ^^^^^^^^^^^^ help: consider: `0b11_0110_i64`
   |
   = note: `-D unreadable-literal` implied by `-D warnings`
 
 error: long literal lacking separators
- --> $DIR/unreadable_literal.rs:7:29
+ --> $DIR/unreadable_literal.rs:7:30
   |
-7 |     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
-  |                             ^^^^^^^^^^^^^^^^^^^ help: consider: `0x123_4567_8901_usize`
+7 |     let bad = (0b110110_i64, 0x12345678901_usize, 123456_f32, 1.234567_f32);
+  |                              ^^^^^^^^^^^^^^^^^^^ help: consider: `0x123_4567_8901_usize`
 
 error: long literal lacking separators
- --> $DIR/unreadable_literal.rs:7:50
+ --> $DIR/unreadable_literal.rs:7:51
   |
-7 |     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
-  |                                                  ^^^^^^^^^ help: consider: `12_345_f32`
+7 |     let bad = (0b110110_i64, 0x12345678901_usize, 123456_f32, 1.234567_f32);
+  |                                                   ^^^^^^^^^^ help: consider: `123_456_f32`
 
 error: long literal lacking separators
- --> $DIR/unreadable_literal.rs:7:61
+ --> $DIR/unreadable_literal.rs:7:63
   |
-7 |     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
-  |                                                             ^^^^^^^^^^^ help: consider: `1.234_56_f32`
+7 |     let bad = (0b110110_i64, 0x12345678901_usize, 123456_f32, 1.234567_f32);
+  |                                                               ^^^^^^^^^^^^ help: consider: `1.234_567_f32`
 
 error: long literal lacking separators
  --> $DIR/unreadable_literal.rs:9:19
   |
-9 |     let bad_sci = 1.12345e1;
-  |                   ^^^^^^^^^ help: consider: `1.123_45e1`
+9 |     let bad_sci = 1.123456e1;
+  |                   ^^^^^^^^^^ help: consider: `1.123_456e1`
 
 error: aborting due to 5 previous errors