diff --git a/internal/adapter/openai/handler_toolcall_test.go b/internal/adapter/openai/handler_toolcall_test.go
index e071d542..e595f53c 100644
--- a/internal/adapter/openai/handler_toolcall_test.go
+++ b/internal/adapter/openai/handler_toolcall_test.go
@@ -275,7 +275,7 @@ func TestHandleNonStreamFencedToolCallExamplePromotesToolCall(t *testing.T) {
 	TestHandleNonStreamFencedToolCallExampleDoesNotPromoteToolCall(t)
 }
 
-func TestHandleNonStreamReturns502WhenUpstreamOutputEmpty(t *testing.T) {
+func TestHandleNonStreamReturns429WhenUpstreamOutputEmpty(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
 		`data: {"p":"response/content","v":""}`,
@@ -284,8 +284,8 @@ func TestHandleNonStreamReturns502WhenUpstreamOutputEmpty(t *testing.T) {
 	rec := httptest.NewRecorder()
 
 	h.handleNonStream(rec, context.Background(), resp, "cid-empty", "deepseek-chat", "prompt", false, nil)
-	if rec.Code != http.StatusBadGateway {
-		t.Fatalf("expected status 502 for empty upstream output, got %d body=%s", rec.Code, rec.Body.String())
+	if rec.Code != http.StatusTooManyRequests {
+		t.Fatalf("expected status 429 for empty upstream output, got %d body=%s", rec.Code, rec.Body.String())
 	}
 	out := decodeJSONBody(t, rec.Body.String())
 	errObj, _ := out["error"].(map[string]any)
diff --git a/internal/adapter/openai/responses_stream_test.go b/internal/adapter/openai/responses_stream_test.go
index 60abe195..138e9d00 100644
--- a/internal/adapter/openai/responses_stream_test.go
+++ b/internal/adapter/openai/responses_stream_test.go
@@ -627,7 +627,7 @@ func TestHandleResponsesNonStreamToolChoiceNoneStillAllowsFunctionCall(t *testin
 	}
 }
 
-func TestHandleResponsesNonStreamReturns502WhenUpstreamOutputEmpty(t *testing.T) {
+func TestHandleResponsesNonStreamReturns429WhenUpstreamOutputEmpty(t *testing.T) {
 	h := &Handler{}
 	rec := httptest.NewRecorder()
 	resp := &http.Response{
@@ -639,8 +639,8 @@ func TestHandleResponsesNonStreamReturns502WhenUpstreamOutputEmpty(t *testing.T)
 	}
 
 	h.handleResponsesNonStream(rec, resp, "owner-a", "resp_test", "deepseek-chat", "prompt", false, nil, util.DefaultToolChoicePolicy(), "")
-	if rec.Code != http.StatusBadGateway {
-		t.Fatalf("expected 502 for empty upstream output, got %d body=%s", rec.Code, rec.Body.String())
+	if rec.Code != http.StatusTooManyRequests {
+		t.Fatalf("expected 429 for empty upstream output, got %d body=%s", rec.Code, rec.Body.String())
 	}
 	out := decodeJSONBody(t, rec.Body.String())
 	errObj, _ := out["error"].(map[string]any)
diff --git a/internal/adapter/openai/upstream_empty.go b/internal/adapter/openai/upstream_empty.go
index f9401edc..071ffced 100644
--- a/internal/adapter/openai/upstream_empty.go
+++ b/internal/adapter/openai/upstream_empty.go
@@ -10,6 +10,6 @@ func writeUpstreamEmptyOutputError(w http.ResponseWriter, thinking, text string,
 		writeOpenAIErrorWithCode(w, http.StatusBadRequest, "Upstream content filtered the response and returned no output.", "content_filter")
 		return true
 	}
-	writeOpenAIErrorWithCode(w, http.StatusBadGateway, "Upstream model returned empty output.", "upstream_empty_output")
+	writeOpenAIErrorWithCode(w, http.StatusTooManyRequests, "Upstream model returned empty output.", "upstream_empty_output")
 	return true
 }