diff --git a/pyproject.toml b/pyproject.toml
index 5de79ec..1ec4d42 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ dynamic = ["version"]
 dependencies = [
     "DLite-Python ~=0.5.29,<0.5.40",
     "eval-type-backport >=0.3.1,<0.5.0",
-    "fastapi ~=0.136.0",
+    "fastapi >=0.136,<0.138",
     "optimade[mongo] ~=1.4",
     "oteapi-core >=1.0.1,<2",
     "oteapi-dlite >=1.0.1,<2",