diff --git a/charts/api/Chart.yaml b/charts/api/Chart.yaml
index adbd3e1..5ca0e3a 100644
--- a/charts/api/Chart.yaml
+++ b/charts/api/Chart.yaml
@@ -2,7 +2,7 @@ apiVersion: v1
 appVersion: "1.0"
 description: A Helm chart for the WBStack API
 name: api
-version: 0.21.0
+version: 0.22.0
 home: https://github.com/wbstack
 maintainers:
   - name: WBstack
diff --git a/charts/api/templates/_helpers.tpl b/charts/api/templates/_helpers.tpl
index fa63d56..b025a52 100644
--- a/charts/api/templates/_helpers.tpl
+++ b/charts/api/templates/_helpers.tpl
@@ -64,6 +64,10 @@ Common lists of environment variables
 - name: WBSTACK_SUMMARY_INACTIVE_THRESHOLD
   value: {{ .Values.wbstack.summaryInactiveThreshold | quote }}
 {{- end }}
+{{- if .Values.wbstack.summaryCreationRateRanges }}
+- name: WBSTACK_SUMMARY_CREATION_RATE_RANGES
+  value: {{ join "," .Values.wbstack.summaryCreationRateRanges | quote }}
+{{- end }}
 {{- if .Values.wbstack.contact.mail.recipient }}
 - name: WBSTACK_CONTACT_MAIL_RECIPIENT
   value: {{ .Values.wbstack.contact.mail.recipient | quote }}
diff --git a/charts/api/values.yaml b/charts/api/values.yaml
index 7f69d3e..ef4f315 100644
--- a/charts/api/values.yaml
+++ b/charts/api/values.yaml
@@ -49,6 +49,10 @@ platform:
 
 wbstack:
   summaryInactiveThreshold:
+  # Ranges are passed in duration strings as expected by a PHP DateInterval
+  # constructor: https://www.php.net/manual/en/dateinterval.construct.php
+  # E.g. PT6H (6 hours) or P30D (30 days)
+  summaryCreationRateRanges: []
   maxWikisPerUser:
   subdomainSuffix: ".undefined.nohost"
   uiurl: