diff --git a/ci/init-external-repos.sh b/ci/init-external-repos.sh
index 277e372eb5..43814a69c5 100755
--- a/ci/init-external-repos.sh
+++ b/ci/init-external-repos.sh
@@ -31,9 +31,10 @@ fi
 make update-traces
 cd ..
 
+# When running in Cirrus for the main repo, try to clone the private testsuite.
 # Note that this script is also called when populating the public cache, so
 # the zeek-testing-private dir could have been created/populated already.
-if [[ -n "${CIRRUS_CI}" ]] && [[ ! -d zeek-testing-private ]]; then
+if [[ -n "${CIRRUS_CI}" ]] && [[ "${CIRRUS_REPO_OWNER}" == "zeek" ]] && [[ ! -d zeek-testing-private ]]; then
     # If we're running this on Cirrus, the SSH key won't be available to PRs,
     # so don't make any of this fail the task in that case.  (But technically,
     # the key is also available in PRs for people with write access to the