diff --git a/src/FunctionAppResolver.ts b/src/FunctionAppResolver.ts
index 14a3f887b..7f5031c51 100644
--- a/src/FunctionAppResolver.ts
+++ b/src/FunctionAppResolver.ts
@@ -1,18 +1,28 @@
-import { getResourceGroupFromId } from "@microsoft/vscode-azext-azureutils";
-import { callWithTelemetryAndErrorHandling, IActionContext, ISubscriptionContext, nonNullProp } from "@microsoft/vscode-azext-utils";
+import { Site } from "@azure/arm-appservice";
+import { uiUtils } from "@microsoft/vscode-azext-azureutils";
+import { IActionContext, ISubscriptionContext, callWithTelemetryAndErrorHandling, nonNullProp, nonNullValue } from "@microsoft/vscode-azext-utils";
 import { AppResource, AppResourceResolver } from "@microsoft/vscode-azext-utils/hostapi";
 import { ResolvedFunctionAppResource } from "./tree/ResolvedFunctionAppResource";
 import { createWebSiteClient } from "./utils/azureClients";
 
 export class FunctionAppResolver implements AppResourceResolver {
+
+    private siteCacheLastUpdated = 0;
+    private siteCache: Map<string, Site> = new Map<string, Site>();
+
     public async resolveResource(subContext: ISubscriptionContext, resource: AppResource): Promise<ResolvedFunctionAppResource | undefined> {
         return await callWithTelemetryAndErrorHandling('resolveResource', async (context: IActionContext) => {
             const client = await createWebSiteClient({ ...context, ...subContext });
-            const rg = getResourceGroupFromId(nonNullProp(resource, 'id'));
-            const name = nonNullProp(resource, 'name');
 
-            const site = await client.webApps.get(rg, name);
-            return ResolvedFunctionAppResource.createResolvedFunctionAppResource(context, subContext, site);
+            if (this.siteCacheLastUpdated < Date.now() - 1000 * 3) {
+                this.siteCache.clear();
+                const sites = await uiUtils.listAllIterator(client.webApps.list());
+                sites.forEach(site => this.siteCache.set(nonNullProp(site, 'id').toLowerCase(), site));
+                this.siteCacheLastUpdated = Date.now();
+            }
+
+            const site = this.siteCache.get(nonNullProp(resource, 'id').toLowerCase());
+            return ResolvedFunctionAppResource.createResolvedFunctionAppResource(context, subContext, nonNullValue(site));
         });
     }