diff --git a/tox.ini b/tox.ini
index 18078536c..5dbdafce3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -536,7 +536,7 @@ commands_pre =
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-celery[test]
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-pika[test]
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-aio-pika[test]
-  python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-sklearn[test]
+  python3.9 -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-sklearn[test]
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-redis[test]
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-remoulade[test]
   python -m pip install -e {toxinidir}/instrumentation/opentelemetry-instrumentation-fastapi[test]