diff --git a/CHANGELOG.md b/CHANGELOG.md
index 934ab970b32..1d606e53323 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 * [CHANGE] Compactor: delete source and output blocks from local disk on compaction failed, to reduce likelihood that subsequent compactions fail because of no space left on disk. #2261
 * [CHANGE] Ruler: Remove unused CLI flags `-ruler.search-pending-for` and `-ruler.flush-period` (and their respective YAML config options). #2288
+* [ENHANCEMENT] Alertmanager: Allow the HTTP `proxy_url` configuration option in the receiver's configuration. #2317
 * [BUGFIX] Compactor: log the actual error on compaction failed. #2261
 
 ### Mixin
diff --git a/pkg/alertmanager/api.go b/pkg/alertmanager/api.go
index 95cc98a2541..7ed93454b73 100644
--- a/pkg/alertmanager/api.go
+++ b/pkg/alertmanager/api.go
@@ -422,9 +422,6 @@ func validateReceiverHTTPConfig(cfg commoncfg.HTTPClientConfig) error {
 	if cfg.BearerTokenFile != "" {
 		return errPasswordFileNotAllowed
 	}
-	if cfg.ProxyURL.URL != nil {
-		return errProxyURLNotAllowed
-	}
 	if cfg.OAuth2 != nil && cfg.OAuth2.ClientSecretFile != "" {
 		return errOAuth2SecretFileNotAllowed
 	}
diff --git a/pkg/alertmanager/api_test.go b/pkg/alertmanager/api_test.go
index 7b8b8f7eb12..23db41f10ee 100644
--- a/pkg/alertmanager/api_test.go
+++ b/pkg/alertmanager/api_test.go
@@ -317,7 +317,6 @@ alertmanager_config: |
         client_secret: xxx
         token_url: http://example.com
         proxy_url: http://example.com
-
   route:
     receiver: 'default-receiver'
   receivers:
@@ -428,23 +427,6 @@ alertmanager_config: |
               token_url: http://example.com
               client_secret: xxx
               proxy_url: http://localhost
-
-  route:
-    receiver: 'default-receiver'
-`,
-			err: errors.Wrap(errProxyURLNotAllowed, "error validating Alertmanager config"),
-		},
-		{
-			name: "Should return error if receiver's HTTP proxy_url is set",
-			cfg: `
-alertmanager_config: |
-  receivers:
-    - name: default-receiver
-      webhook_configs:
-        - url: http://localhost
-          http_config:
-            proxy_url: http://localhost
-
   route:
     receiver: 'default-receiver'
 `,