diff --git a/pyproject.toml b/pyproject.toml
index 270af42a..72319351 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,7 @@ dependencies = [
   "geocoder (>=1.38.1,<2.0.0)",
   "pydantic-extra-types (>=2.10.5,<3.0.0)",
   "pyyaml (>=6.0.2,<7.0.0)",
-  "flatdict (==4.0.0)",
+  "flatdict (==4.1.0)",
   "pytest (>=9.0.3,<10.0.0)",
   "unyt (>=3.1.0,<4.0.0)",
 ]