diff --git a/.changelog/10039.txt b/.changelog/10039.txt
new file mode 100644
index 0000000000..90bd541c79
--- /dev/null
+++ b/.changelog/10039.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+ui: ensure proxy instance API requests perform blocking queries correctly
+```
diff --git a/ui/packages/consul-ui/app/services/repository/proxy.js b/ui/packages/consul-ui/app/services/repository/proxy.js
index ea76d7e701..8202bf877c 100644
--- a/ui/packages/consul-ui/app/services/repository/proxy.js
+++ b/ui/packages/consul-ui/app/services/repository/proxy.js
@@ -36,7 +36,7 @@ export default class ProxyService extends RepositoryService {
   }
 
   @dataSource('/:ns/:dc/proxy-instance/:serviceId/:node/:id')
-  findInstanceBySlug(params, nspace, configuration) {
+  findInstanceBySlug(params, configuration) {
     return this.findAllBySlug(params, configuration).then(function(items) {
       let res = {};
       if (get(items, 'length') > 0) {