diff --git a/protocol/protocol.tex b/protocol/protocol.tex
index 588144d0..5eb93892 100644
--- a/protocol/protocol.tex
+++ b/protocol/protocol.tex
@@ -10248,6 +10248,15 @@ Peter Newell's illustration of the Jubjub bird, from \cite{Carroll1902}.
 \intropart
 \lsection{Change History}{changehistory}
 
+\historyentry{2020.1.0}{2020-02-06}
+
+\begin{itemize}
+    \item Add acknowledgements to Henry de Valence, Deirdre Connolly, Chelsea Komlo,
+          and Zancas Wilcox.
+    \item Add an acknowledgement to Trail of Bits for their security audit.
+    \item Change indices in the \incrementalMerkleTree diagram to be zero-based.
+\end{itemize}
+
 \historyentry{2019.0.9}{2019-12-27}
 
 \begin{itemize}