diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d6e482..412758f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+## Fixed
+
+- Remove `Default` derive on CDS time provider. This can lead to uninitialized preamble fields.
+
 ## Changed
 
 - `serde` support is now optional and behind the `serde` feature.
@@ -19,6 +23,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   The function now returns the remaining slice as well.
 - All CDS specific functionality was moved into the `cds` submodule of the `time`
   module. `CdsShortTimeProvider` was renamed to `TimeProvider`.
+  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/3
 
 ## Added
 
diff --git a/src/tc.rs b/src/tc.rs
index 9db2e86..268e5eb 100644
--- a/src/tc.rs
+++ b/src/tc.rs
@@ -279,6 +279,10 @@ impl<'slice> PusTc<'slice> {
         )
     }
 
+    pub fn sp_header(&self) -> &SpHeader {
+        &self.sp_header
+    }
+
     pub fn len_packed(&self) -> usize {
         let mut length = PUS_TC_MIN_LEN_WITHOUT_APP_DATA;
         if let Some(app_data) = self.app_data {