diff --git a/pyproject.toml b/pyproject.toml
index 312dab5..5debfb4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,7 +38,7 @@ dependencies = [
     "unstructured[pdf,md]>=0.16.0,<1.0",
     "pymupdf>=1.25.0,<2.0",
     # Observability
-    "langfuse>=2.56.0,<3.0",
+    "langfuse>=2.56.0,<5.0",
     "opentelemetry-api>=1.28.0,<2.0",
     "opentelemetry-sdk>=1.28.0,<2.0",
     "opentelemetry-exporter-otlp>=1.28.0,<2.0",