diff --git a/retrieval/scrape.go b/retrieval/scrape.go
index beb965770..abda0c476 100644
--- a/retrieval/scrape.go
+++ b/retrieval/scrape.go
@@ -397,7 +397,7 @@ type targetScraper struct {
 	buf   *bufio.Reader
 }
 
-const acceptHeader = `application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.7,text/plain;version=0.0.4;q=0.3,*/*;q=0.1`
+const acceptHeader = `text/plain;version=0.0.4;q=1,*/*;q=0.1`
 
 var userAgentHeader = fmt.Sprintf("Prometheus/%s", version.Version)
 
@@ -407,8 +407,7 @@ func (s *targetScraper) scrape(ctx context.Context, w io.Writer) error {
 		if err != nil {
 			return err
 		}
-		// Disable accept header to always negotiate for text format.
-		// req.Header.Add("Accept", acceptHeader)
+		req.Header.Add("Accept", acceptHeader)
 		req.Header.Add("Accept-Encoding", "gzip")
 		req.Header.Set("User-Agent", userAgentHeader)
 		req.Header.Set("X-Prometheus-Scrape-Timeout-Seconds", fmt.Sprintf("%f", s.timeout.Seconds()))
diff --git a/retrieval/scrape_test.go b/retrieval/scrape_test.go
index a9ca87cd2..b267bbc40 100644
--- a/retrieval/scrape_test.go
+++ b/retrieval/scrape_test.go
@@ -895,11 +895,14 @@ func TestTargetScraperScrapeOK(t *testing.T) {
 
 	server := httptest.NewServer(
 		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			accept := r.Header.Get("Accept")
+			if !strings.HasPrefix(accept, "text/plain;") {
+				t.Errorf("Expected Accept header to prefer text/plain, got %q", accept)
+			}
+
 			timeout := r.Header.Get("X-Prometheus-Scrape-Timeout-Seconds")
 			if timeout != expectedTimeout {
-				t.Errorf("Scrape timeout did not match expected timeout")
-				t.Errorf("Expected: %v", expectedTimeout)
-				t.Fatalf("Got: %v", timeout)
+				t.Errorf("Expected scrape timeout header %q, got %q", expectedTimeout, timeout)
 			}
 
 			w.Header().Set("Content-Type", `text/plain; version=0.0.4`)