diff --git a/ci/prepare.py b/ci/prepare.py
index da3b9e18cf3d8195d36eacf6685ea30923912ce0..df1f6e4c346d2d19edd234c99cfbb6e70c4a395d 100755
--- a/ci/prepare.py
+++ b/ci/prepare.py
@@ -47,9 +47,9 @@ def extract_cmake_package(artifacts, name):
 
 if __name__ == "__main__":
     if system() == "Windows":
-        job_stem = "package windows"
+        job_stem = "package: [windows]"
     elif system() == "Linux":
-        job_stem = "package centos"
+        job_stem = "package: [centos]"
     else:
         assert False