diff --git a/openshift/e2e-tests.sh b/openshift/e2e-tests.sh
index 2aaf64225a..27d8509575 100755
--- a/openshift/e2e-tests.sh
+++ b/openshift/e2e-tests.sh
@@ -7,8 +7,12 @@ echo "Running e2e-tests.sh"
 unset GOFLAGS
 tmp="$(mktemp -d)"
 
-# Default branch for both CCAPIO and this repo should be `main`.
-CCAPIO_BASE_REF=$PULL_BASE_REF
+if [ "${PULL_BASE_REF}" == "master" ]; then
+  # the default branch for cluster-capi-operator is main.
+  CCAPIO_BASE_REF="main"
+else
+  CCAPIO_BASE_REF=$PULL_BASE_REF
+fi
 
 echo "cloning github.com/openshift/cluster-capi-operator at branch '$CCAPIO_BASE_REF'"
 git clone --single-branch --branch="$CCAPIO_BASE_REF" --depth=1 "https://github.com/openshift/cluster-capi-operator.git" "$tmp"