diff --git a/src/header/shared/quality_item.rs b/src/header/shared/quality_item.rs
index 497df37a0d..1f976a869a 100644
--- a/src/header/shared/quality_item.rs
+++ b/src/header/shared/quality_item.rs
@@ -11,7 +11,7 @@ use std::str;
 /// # Implementation notes
 ///
 /// The quality value is defined as a number between 0 and 1 with three decimal places. This means
-/// there are 1000 possible values. Since floating point numbers are not exact and the smallest
+/// there are 1001 possible values. Since floating point numbers are not exact and the smallest
 /// floating point data type (`f32`) consumes four bytes, hyper uses an `u16` value to store the
 /// quality internally. For performance reasons you may set quality directly to a value between
 /// 0 and 1000 e.g. `Quality(532)` matches the quality `q=0.532`.