diff --git a/pyproject.toml b/pyproject.toml
index 460644463a..4085593047 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,7 @@ dependencies = [
   "opentelemetry-exporter-gcp-trace>=1.9.0, <2.0.0",
   "opentelemetry-exporter-otlp-proto-http>=1.36.0",
   "opentelemetry-resourcedetector-gcp>=1.9.0a0, <2.0.0",
-  "opentelemetry-sdk>=1.36.0, <1.39.0",
+  "opentelemetry-sdk>=1.36.0, <1.40.0",
   "pyarrow>=14.0.0",
   "pydantic>=2.7.0, <3.0.0",                                 # For data validation/models
   "python-dateutil>=2.9.0.post0, <3.0.0",                    # For Vertext AI Session Service