diff --git a/dev-requirements.txt b/dev-requirements.txt
index bb37437..6344ec0 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -90,7 +90,7 @@ opentelemetry-semantic-conventions==0.54b1
     #   elastic-opentelemetry (pyproject.toml)
     #   opentelemetry-instrumentation
     #   opentelemetry-sdk
-oteltest==0.24.0
+oteltest==0.39.0
     # via elastic-opentelemetry (pyproject.toml)
 packaging==25.0
     # via
diff --git a/pyproject.toml b/pyproject.toml
index 6c8ccad..4d5ea26 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ dependencies = [
 ]
 
 [project.optional-dependencies]
-dev = ["pytest", "pip-tools", "oteltest==0.24.0", "leb128"]
+dev = ["pytest", "pip-tools", "oteltest==0.39.0", "leb128"]
 
 [project.entry-points.opentelemetry_configurator]
 configurator = "elasticotel.distro:ElasticOpenTelemetryConfigurator"