diff --git a/CHANGELOG.md b/CHANGELOG.md
index badb9efe..b937934e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 # Version 1.1.3
 
+- reorganised basis functions code into its own submodule `openghg_inversions.basis`. This submodule contains the basis function algorithms, functions to call those algorithms, and the basis function wrapper that was previously in `get_data.py`. [#PR 87](https://github.com/openghg/openghg_inversions/pull/87)
+
 - `combine_datasets` loads data before reindexing, to avoid a performance problem (
 `reindex_like` is very slow if dataset not loaded into memory pydata/xarray#8945). Also, the default method has been set to `nearest` instead of `ffill`, since `ffill` tends to create NaNs in the first lat/lon coordinates. [#PR 87](https://github.com/openghg/openghg_inversions/pull/87)