diff --git a/ct-install.yaml b/ct-install.yaml
index 2fb25f34e..ee24e5d7e 100644
--- a/ct-install.yaml
+++ b/ct-install.yaml
@@ -1,5 +1,16 @@
+# Configuration for chart-testing (ct) install command
+# See: https://github.com/helm/chart-testing
+
 chart-dirs:
   - deploy/charts
 validate-maintainers: false
 remote: origin
 target-branch: main
+
+# Install all charts, not just changed ones.
+# This is required because the operator chart depends on the operator-crds chart.
+# Without 'all: true', ct only installs charts that have changed in the PR.
+# If a PR only changes the operator chart (not operator-crds), the operator
+# will fail to start because the CRDs are not installed in the test cluster.
+# The operator requires CRDs at startup to create field indexes (e.g., spec.groupRef).
+all: true