diff --git a/openwhisk-python-simple/serverless.yml b/openwhisk-python-simple/serverless.yml
index c65530cd0..176ed25c0 100644
--- a/openwhisk-python-simple/serverless.yml
+++ b/openwhisk-python-simple/serverless.yml
@@ -2,7 +2,7 @@ service: python-service
 
 provider:
   name: openwhisk
-  runtime: python
+  runtime: python:3
 
 functions:
   greeting: