diff --git a/packages/arcgis-rest-portal/src/groups/get.ts b/packages/arcgis-rest-portal/src/groups/get.ts
index 491d46d13d..bfac9603b2 100644
--- a/packages/arcgis-rest-portal/src/groups/get.ts
+++ b/packages/arcgis-rest-portal/src/groups/get.ts
@@ -136,15 +136,12 @@ export interface ISearchGroupUsersResult {
  */
 export function searchGroupUsers(
   id: string,
-  searchOptions: ISearchGroupUsersOptions
+  searchOptions?: ISearchGroupUsersOptions
 ): Promise<ISearchGroupUsersResult> {
   const url = `${getPortalUrl(searchOptions)}/community/groups/${id}/userlist`;
-  const options = appendCustomParams<ISearchGroupUsersOptions>(
-    searchOptions,
-    ["name", "num", "start", "sortField", "sortOrder", "joined", "memberType"],
-    {
-      httpMethod: "GET"
-    }
-  );
+  const options: IRequestOptions = {
+    ...{ httpMethod: "GET" },
+    ...searchOptions
+  };
   return request(url, options);
 }
diff --git a/packages/arcgis-rest-portal/test/groups/get.test.ts b/packages/arcgis-rest-portal/test/groups/get.test.ts
index 4cc3a7f41f..beeeac5df0 100644
--- a/packages/arcgis-rest-portal/test/groups/get.test.ts
+++ b/packages/arcgis-rest-portal/test/groups/get.test.ts
@@ -104,33 +104,54 @@ describe("groups", () => {
         });
     });
 
-    it("should search group users", done => {
-      fetchMock.once("*", SearchGroupUsersResponse);
+    describe("search group users", function() {
+      it("should search group users", done => {
+        fetchMock.once("*", SearchGroupUsersResponse);
 
-      searchGroupUsers("5bc", {
-        params: {
-          name: "jupe",
-          sortField: "fullname",
-          sortOrder: "asc",
-          num: 2,
-          start: 2,
-          joined: [null, 123456],
-          memberType: "member"
-        },
-        ...MOCK_REQOPTS
-      })
-        .then(response => {
-          expect(fetchMock.called()).toEqual(true);
-          const [url, options]: [string, RequestInit] = fetchMock.lastCall("*");
-          expect(url).toEqual(
-            "https://myorg.maps.arcgis.com/sharing/rest/community/groups/5bc/userlist?f=json&name=jupe&sortField=fullname&sortOrder=asc&num=2&start=2&joined=%2C123456&memberType=member&token=fake-token"
-          );
-          expect(options.method).toBe("GET");
-          done();
+        searchGroupUsers("5bc", {
+          params: {
+            name: "jupe",
+            sortField: "fullname",
+            sortOrder: "asc",
+            num: 2,
+            start: 2,
+            joined: [null, 123456],
+            memberType: "member"
+          },
+          ...MOCK_REQOPTS
         })
-        .catch(e => {
-          fail(e);
-        });
+          .then(response => {
+            expect(fetchMock.called()).toEqual(true);
+            const [url, options]: [string, RequestInit] = fetchMock.lastCall(
+              "*"
+            );
+            expect(url).toEqual(
+              "https://myorg.maps.arcgis.com/sharing/rest/community/groups/5bc/userlist?f=json&name=jupe&sortField=fullname&sortOrder=asc&num=2&start=2&joined=%2C123456&memberType=member&token=fake-token"
+            );
+            expect(options.method).toBe("GET");
+            done();
+          })
+          .catch(e => {
+            fail(e);
+          });
+      });
+
+      it("shouldn't require searchOptions", done => {
+        fetchMock.once("*", SearchGroupUsersResponse);
+
+        searchGroupUsers("5bc")
+          .then(_ => {
+            expect(fetchMock.called()).toEqual(true);
+            const [__, options]: [string, RequestInit] = fetchMock.lastCall(
+              "*"
+            );
+            expect(options.method).toBe("GET");
+            done();
+          })
+          .catch(e => {
+            fail(e);
+          });
+      });
     });
   });
 });