diff --git a/graphql/handler/transport/http_post.go b/graphql/handler/transport/http_post.go
index 985f8db2941..085f60a910f 100644
--- a/graphql/handler/transport/http_post.go
+++ b/graphql/handler/transport/http_post.go
@@ -27,6 +27,10 @@ func (h POST) Supports(r *http.Request) bool {
 		return false
 	}
 
+	if strings.Contains(r.Header.Get("Accept"), "text/event-stream") {
+		return false
+	}
+
 	mediaType, _, err := mime.ParseMediaType(r.Header.Get("Content-Type"))
 	if err != nil {
 		return false
diff --git a/graphql/handler/transport/http_post_test.go b/graphql/handler/transport/http_post_test.go
index 97ef3be6686..28095d856bc 100644
--- a/graphql/handler/transport/http_post_test.go
+++ b/graphql/handler/transport/http_post_test.go
@@ -96,6 +96,22 @@ func TestPOST(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("validate SSE", func(t *testing.T) {
+		doReq := func(handler http.Handler, method string, target string, body string) *httptest.ResponseRecorder {
+			r := httptest.NewRequest(method, target, strings.NewReader(body))
+			r.Header.Set("Content-Type", "application/json")
+			r.Header.Set("Accept", "text/event-stream")
+			w := httptest.NewRecorder()
+
+			handler.ServeHTTP(w, r)
+			return w
+		}
+
+		resp := doReq(h, "POST", "/graphql", `{"query":"{ name }"}`)
+		assert.Equal(t, http.StatusBadRequest, resp.Code, resp.Body.String())
+		assert.Equal(t, `{"errors":[{"message":"transport not supported"}],"data":null}`, resp.Body.String())
+	})
 }
 
 func doRequest(handler http.Handler, method, target, body, contentType string) *httptest.ResponseRecorder {