diff --git a/packages/react-dom-bindings/src/server/ReactDOMLegacyServerStreamConfig.js b/packages/react-dom-bindings/src/server/ReactDOMLegacyServerStreamConfig.js
index 9b4020e998c5e..1988170779e4c 100644
--- a/packages/react-dom-bindings/src/server/ReactDOMLegacyServerStreamConfig.js
+++ b/packages/react-dom-bindings/src/server/ReactDOMLegacyServerStreamConfig.js
@@ -12,8 +12,8 @@ export interface Destination {
   destroy(error: Error): mixed;
 }
 
-export type PrecomputedChunk = string;
-export type Chunk = string;
+export opaque type PrecomputedChunk = string;
+export opaque type Chunk = string;
 
 export function scheduleWork(callback: () => void) {
   callback();
diff --git a/packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js b/packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js
index c62945a02520a..ba6940fdfd7a4 100644
--- a/packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js
+++ b/packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js
@@ -2385,7 +2385,7 @@ export function writeInitialResources(
     } else {
       target.push(
         precedencePlaceholderStart,
-        escapeTextForBrowser(stringToChunk(precedence)),
+        stringToChunk(escapeTextForBrowser(precedence)),
         precedencePlaceholderEnd,
       );
     }
@@ -2417,7 +2417,7 @@ export function writeInitialResources(
       case 'title': {
         pushStartTitleImpl(target, r.props, responseState);
         if (typeof r.props.children === 'string') {
-          target.push(escapeTextForBrowser(stringToChunk(r.props.children)));
+          target.push(stringToChunk(escapeTextForBrowser(r.props.children)));
         }
         pushEndInstance(target, target, 'title', r.props);
         break;
@@ -2518,7 +2518,7 @@ export function writeImmediateResources(
       case 'title': {
         pushStartTitleImpl(target, r.props, responseState);
         if (typeof r.props.children === 'string') {
-          target.push(escapeTextForBrowser(stringToChunk(r.props.children)));
+          target.push(stringToChunk(escapeTextForBrowser(r.props.children)));
         }
         pushEndInstance(target, target, 'title', r.props);
         break;
diff --git a/packages/react-dom-bindings/src/server/escapeTextForBrowser.js b/packages/react-dom-bindings/src/server/escapeTextForBrowser.js
index 0c8abd00938c5..90407972ba02a 100644
--- a/packages/react-dom-bindings/src/server/escapeTextForBrowser.js
+++ b/packages/react-dom-bindings/src/server/escapeTextForBrowser.js
@@ -28,6 +28,8 @@
  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * @flow
  */
 
 // code copied and modified from escape-html
@@ -103,12 +105,12 @@ function escapeHtml(string) {
  * @param {*} text Text value to escape.
  * @return {string} An escaped string.
  */
-function escapeTextForBrowser(text) {
+function escapeTextForBrowser(text: string | number | boolean): string {
   if (typeof text === 'boolean' || typeof text === 'number') {
     // this shortcircuit helps perf for types that we know will never have
     // special characters, especially given that this function is used often
     // for numeric dom ids.
-    return '' + text;
+    return '' + (text: any);
   }
   return escapeHtml(text);
 }
diff --git a/packages/react-dom/src/__tests__/ReactDOMFizzServerBrowser-test.js b/packages/react-dom/src/__tests__/ReactDOMFizzServerBrowser-test.js
index e3d5808dc1080..1b1357b0e9cea 100644
--- a/packages/react-dom/src/__tests__/ReactDOMFizzServerBrowser-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMFizzServerBrowser-test.js
@@ -484,4 +484,22 @@ describe('ReactDOMFizzServerBrowser', () => {
 
     expect(errors).toEqual(['uh oh', 'uh oh']);
   });
+
+  // https://github.com/facebook/react/pull/25534/files - fix transposed escape functions
+  // @gate enableFloat
+  it('should encode title properly', async () => {
+    const stream = await ReactDOMFizzServer.renderToReadableStream(
+      <html>
+        <head>
+          <title>foo</title>
+        </head>
+        <body>bar</body>
+      </html>,
+    );
+
+    const result = await readResult(stream);
+    expect(result).toEqual(
+      '<!DOCTYPE html><html><head><title>foo</title></title></head><body>bar</body></html>',
+    );
+  });
 });
diff --git a/packages/react-server-dom-relay/src/ReactServerStreamConfigFB.js b/packages/react-server-dom-relay/src/ReactServerStreamConfigFB.js
index 9932db14bd87c..ee6b151ead541 100644
--- a/packages/react-server-dom-relay/src/ReactServerStreamConfigFB.js
+++ b/packages/react-server-dom-relay/src/ReactServerStreamConfigFB.js
@@ -14,8 +14,8 @@ export type Destination = {
   error: mixed,
 };
 
-export type PrecomputedChunk = string;
-export type Chunk = string;
+export opaque type PrecomputedChunk = string;
+export opaque type Chunk = string;
 
 export function scheduleWork(callback: () => void) {
   // We don't schedule work in this model, and instead expect performWork to always be called repeatedly.
diff --git a/packages/react-server/src/ReactServerStreamConfigBrowser.js b/packages/react-server/src/ReactServerStreamConfigBrowser.js
index d2f4d074bf2df..f48273bbadfac 100644
--- a/packages/react-server/src/ReactServerStreamConfigBrowser.js
+++ b/packages/react-server/src/ReactServerStreamConfigBrowser.js
@@ -10,7 +10,7 @@
 export type Destination = ReadableStreamController;
 
 export type PrecomputedChunk = Uint8Array;
-export type Chunk = Uint8Array;
+export opaque type Chunk = Uint8Array;
 
 export function scheduleWork(callback: () => void) {
   callback();
diff --git a/packages/react-server/src/ReactServerStreamConfigNode.js b/packages/react-server/src/ReactServerStreamConfigNode.js
index 4ed822e53b381..282dd193182b3 100644
--- a/packages/react-server/src/ReactServerStreamConfigNode.js
+++ b/packages/react-server/src/ReactServerStreamConfigNode.js
@@ -17,7 +17,7 @@ interface MightBeFlushable {
 export type Destination = Writable & MightBeFlushable;
 
 export type PrecomputedChunk = Uint8Array;
-export type Chunk = string;
+export opaque type Chunk = string;
 
 export function scheduleWork(callback: () => void) {
   setImmediate(callback);