diff --git a/src/proxy/middleware/response/index.ts b/src/proxy/middleware/response/index.ts
index 4fea396..f85664f 100644
--- a/src/proxy/middleware/response/index.ts
+++ b/src/proxy/middleware/response/index.ts
@@ -314,7 +314,11 @@ const handleUpstreamErrors: ProxyResHandlerWithBody = async (
     keyPool.disable(req.key!, "revoked");
     errorPayload.proxy_note = `API key is invalid or revoked. ${tryAgainMessage}`;
   } else if (statusCode === 403) {
-    // Amazon is the only service that returns 403.
+    if (service === "anthropic") {
+      keyPool.disable(req.key!, "revoked");
+      errorPayload.proxy_note = `API key is invalid or revoked. ${tryAgainMessage}`;
+      return;
+    }
     switch (errorType) {
       case "UnrecognizedClientException":
         // Key is invalid.
diff --git a/src/shared/key-management/anthropic/checker.ts b/src/shared/key-management/anthropic/checker.ts
index b930489..e61e608 100644
--- a/src/shared/key-management/anthropic/checker.ts
+++ b/src/shared/key-management/anthropic/checker.ts
@@ -48,13 +48,14 @@ export class AnthropicKeyChecker extends KeyCheckerBase<AnthropicKey> {
   protected handleAxiosError(key: AnthropicKey, error: AxiosError) {
     if (error.response && AnthropicKeyChecker.errorIsAnthropicAPIError(error)) {
       const { status, data } = error.response;
-      if (status === 401) {
+      if (status === 401 || status === 403) {
         this.log.warn(
           { key: key.hash, error: data },
           "Key is invalid or revoked. Disabling key."
         );
         this.updateKey(key.hash, { isDisabled: true, isRevoked: true });
-      } else if (status === 429) {
+      }
+      else if (status === 429) {
         switch (data.error.type) {
           case "rate_limit_error":
             this.log.warn(