diff --git a/lib/proxy/engine/proxy_isolate.dart b/lib/proxy/engine/proxy_isolate.dart
index d865936..a55781e 100644
--- a/lib/proxy/engine/proxy_isolate.dart
+++ b/lib/proxy/engine/proxy_isolate.dart
@@ -469,6 +469,12 @@ class _ProxyIsolateHost {
         details: _requestContextPayload(prompt: resolvedPrompt),
       );
       final payload = await _executeNonStreamRequest(resolvedPrompt, retryTracker: retryTracker);
+	  
+	  final candidates = payload['candidates'] as List?;
+	  if (candidates != null && candidates.isEmpty) {
+		return _errorResponse(502, 'bad_gateway', 'Upstream API returned empty candidates');
+		}
+		
       await _logTrace(
         category: 'chat.completions',
         route: route,
@@ -664,6 +670,12 @@ class _ProxyIsolateHost {
       }
 
       final payload = await _executeNonStreamRequest(resolvedPrompt, retryTracker: retryTracker);
+	  
+	  final candidates = payload['candidates'] as List?;
+	  if (candidates != null && candidates.isEmpty) {
+		return _errorResponse(502, 'bad_gateway', 'Upstream API returned empty candidates');
+		}
+		
       await _logResponsePreview(
         category: 'responses',
         route: route,
diff --git a/lib/proxy/gemini/gemini_code_assist_client.dart b/lib/proxy/gemini/gemini_code_assist_client.dart
index 544d40c..85151c3 100644
--- a/lib/proxy/gemini/gemini_code_assist_client.dart
+++ b/lib/proxy/gemini/gemini_code_assist_client.dart
@@ -161,7 +161,7 @@ const _cloudCodeDomains = <String>{
 };
 const defaultGeminiRequestMaxRetries = 10;
 const defaultGeminiBaseRetryDelay = Duration(seconds: 1);
-const defaultGeminiRequestTimeout = Duration(seconds: 90);
+const defaultGeminiRequestTimeout = Duration(minutes: 5);
 const _maxTransientRequestRetries = 3;
 const _maxRetryable429Delay = Duration(minutes: 1);
 const _maxRetryableTransientDelay = Duration(minutes: 5);