diff --git a/requirements.txt b/requirements.txt
index 50104d7..60f3860 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,4 +11,4 @@ NREL-PySAM
 polars
 numba
 wetterdienst==0.89.0
-marshmallow==3.20.1
+marshmallow==3.26.2