diff --git a/pyproject.toml b/pyproject.toml
index 64c90f3..8ccd82a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,7 +10,7 @@ dynamic = ["version"]
 dependencies = [
     # "frappe~=15.0.0" # Installed and managed by bench.
     "ics~=0.7.2",
-    "tatsu==5.16.0"
+    "tatsu==5.23.0"
 ]
 
 [build-system]