diff --git a/packages/react-dev-utils/WebpackDevServerUtils.js b/packages/react-dev-utils/WebpackDevServerUtils.js
index 0a3e233e641..df428313cca 100644
--- a/packages/react-dev-utils/WebpackDevServerUtils.js
+++ b/packages/react-dev-utils/WebpackDevServerUtils.js
@@ -324,6 +324,11 @@ function prepareProxy(proxy, appPublicFolder) {
       // If this heuristic doesn’t work well for you, use a custom `proxy` object.
       context: function(pathname, req) {
         return (
+          // Resolves an issue with WebSocket (#5280).
+          (!pathname.startsWith("/sockjs-node/") &&
+            req.upgrade &&
+            req.headers.upgrade &&
+            req.headers.upgrade.toLowerCase() === 'websocket') ||
           req.method !== 'GET' ||
           (mayProxy(pathname) &&
             req.headers.accept &&