diff --git a/CHANGELOG.md b/CHANGELOG.md
index ab883f8..e0b1370 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+## Changed
+
+- Moved `CCSDS_HEADER_LEN` constant to the crate root.
+
 # [v0.11.0-rc.2] 2024-04-04
 
 ## Changed
diff --git a/Cargo.toml b/Cargo.toml
index d4d9cd9..9624fd2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "spacepackets"
 version = "0.11.0-rc.2"
 edition = "2021"
-rust-version = "1.61"
+rust-version = "1.65"
 authors = ["Robin Mueller <muellerr@irs.uni-stuttgart.de>"]
 description = "Generic implementations for various CCSDS and ECSS packet standards"
 homepage = "https://egit.irs.uni-stuttgart.de/rust/spacepackets"
diff --git a/src/ecss/mod.rs b/src/ecss/mod.rs
index ad84a81..37345f3 100644
--- a/src/ecss/mod.rs
+++ b/src/ecss/mod.rs
@@ -22,7 +22,6 @@ pub mod tm;
 pub mod verification;
 
 pub type CrcType = u16;
-pub const CCSDS_HEADER_LEN: usize = size_of::<crate::zc::SpHeader>();
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, IntoPrimitive, TryFromPrimitive)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/lib.rs b/src/lib.rs
index 1f82bb5..fa2c3d0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -65,7 +65,6 @@ extern crate alloc;
 #[cfg(any(feature = "std", test))]
 extern crate std;
 
-use crate::ecss::CCSDS_HEADER_LEN;
 use core::{
     fmt::{Debug, Display, Formatter},
     hash::Hash,
@@ -88,6 +87,8 @@ mod private {
     pub trait Sealed {}
 }
 
+pub const CCSDS_HEADER_LEN: usize = core::mem::size_of::<crate::zc::SpHeader>();
+
 /// CRC algorithm used by the PUS standard, the CCSDS TC standard and the CFDP standard.
 pub const CRC_CCITT_FALSE: Crc<u16> = Crc::<u16>::new(&CRC_16_IBM_3740);