diff --git a/core/modules/aggregator/config/schema/aggregator.schema.yml b/core/modules/aggregator/config/schema/aggregator.schema.yml
new file mode 100644
index 0000000..f4a0394
--- /dev/null
+++ b/core/modules/aggregator/config/schema/aggregator.schema.yml
@@ -0,0 +1,41 @@
+# Schema for the configuration files of the aggregator module.
+
+aggregator.settings:
+  type: mapping
+  label: 'Aggregator settings'
+  mapping:
+    fetcher:
+      type: string
+      label: 'Fetcher'
+    parser:
+      type: string
+      label: 'Parser'
+    processors:
+      type: sequence
+      label: 'Processors'
+      sequence:
+        - type: string
+          label: 'Processor'
+    items:
+      type: mapping
+      label: 'Items'
+      mapping:
+        allowed_html:
+          type: string
+          label: 'Allowed HTML tags'
+        teaser_length:
+          type: integer
+          label: 'Length of trimmed description'
+        expire:
+          type: integer
+          label: 'Discard items older than'
+    source:
+      type: mapping
+      label: 'Source'
+      mapping:
+        list_max:
+          type: integer
+          label: 'Number of items shown in listing pages'
+        category_selector:
+            type: string
+            label: 'Select categories using'