diff --git a/packages/ra-ui-materialui/src/button/ExportButton.js b/packages/ra-ui-materialui/src/button/ExportButton.js
index 125bfa11410..d4be01ec854 100644
--- a/packages/ra-ui-materialui/src/button/ExportButton.js
+++ b/packages/ra-ui-materialui/src/button/ExportButton.js
@@ -19,6 +19,38 @@ const sanitizeRestProps = ({
     ...rest
 }) => rest;
 
+/**
+ * Extracts, aggregates and deduplicates the ids of related records
+ *
+ * @example
+ *     const books = [
+ *         { id: 1, author_id: 123, title: 'Pride and Prejudice' },
+ *         { id: 2, author_id: 123, title: 'Sense and Sensibility' },
+ *         { id: 3, author_id: 456, title: 'War and Peace' },
+ *     ];
+ *     getRelatedIds(books, 'author_id'); => [123, 456]
+ *
+ * @example
+ *     const books = [
+ *         { id: 1, tag_ids: [1, 2], title: 'Pride and Prejudice' },
+ *         { id: 2, tag_ids: [2, 3], title: 'Sense and Sensibility' },
+ *         { id: 3, tag_ids: [4], title: 'War and Peace' },
+ *     ];
+ *     getRelatedIds(records, 'tag_ids'); => [1, 2, 3, 4]
+ *
+ * @param {Object[]} records An array of records
+ * @param {string} field the identifier of the record field to use
+ */
+export const getRelatedIds = (records, field) =>
+    Array.from(
+        new Set(
+            records
+                .filter(record => record[field] != null)
+                .map(record => record[field])
+                .reduce((ids, value) => ids.concat(value), [])
+        )
+    );
+
 /**
  * Helper function for calling the data provider with GET_MANY
  * via redux and saga, and getting a Promise in return
@@ -32,16 +64,9 @@ const sanitizeRestProps = ({
  */
 const fetchRelatedRecords = dispatch => (data, field, resource) =>
     new Promise((resolve, reject) => {
-        const sanitizedData = data
-            .filter(record => record[field])
-            .map(record => record[field]);
-
-        // find unique keys
-        const ids = Array.from(new Set(sanitizedData));
-
         dispatch({
             type: CRUD_GET_MANY,
-            payload: { ids },
+            payload: { ids: getRelatedIds(data, field) },
             meta: {
                 resource,
                 fetch: GET_MANY,
diff --git a/packages/ra-ui-materialui/src/button/ExportButton.spec.js b/packages/ra-ui-materialui/src/button/ExportButton.spec.js
new file mode 100644
index 00000000000..a4c332ac739
--- /dev/null
+++ b/packages/ra-ui-materialui/src/button/ExportButton.spec.js
@@ -0,0 +1,30 @@
+import { getRelatedIds } from './ExportButton';
+
+describe('ExportButton', () => {
+    describe('getRelatedIds', () => {
+        it('should ignore null or undefined values', () => {
+            const books = [
+                { id: 1, author_id: 123, title: 'Pride and Prejudice' },
+                { id: 2, author_id: null },
+                { id: 3 },
+            ];
+            expect(getRelatedIds(books, 'author_id')).toEqual([123]);
+        });
+        it('should aggregate scalar related ids', () => {
+            const books = [
+                { id: 1, author_id: 123, title: 'Pride and Prejudice' },
+                { id: 2, author_id: 123, title: 'Sense and Sensibility' },
+                { id: 3, author_id: 456, title: 'War and Peace' },
+            ];
+            expect(getRelatedIds(books, 'author_id')).toEqual([123, 456]);
+        });
+        it('should aggregate arrays of related ids', () => {
+            const books = [
+                { id: 1, tag_ids: [1, 2], title: 'Pride and Prejudice' },
+                { id: 2, tag_ids: [2, 3], title: 'Sense and Sensibility' },
+                { id: 3, tag_ids: [4], title: 'War and Peace' },
+            ];
+            expect(getRelatedIds(books, 'tag_ids')).toEqual([1, 2, 3, 4]);
+        });
+    });
+});