diff --git a/Project.toml b/Project.toml
index 34b69756..e9b6d555 100644
--- a/Project.toml
+++ b/Project.toml
@@ -33,6 +33,7 @@ Catlab = "0.15, 0.16"
 CombinatorialSpaces = "0.5, 0.6"
 ComponentArrays = "0.15"
 DataStructures = "0.18.13"
+DiagrammaticEquations = "0.1"
 Distributions = "0.25"
 FileIO = "1.16"
 GeometryBasics = "0.4.2"