diff --git a/.changeset/fix-pagelayout-overflow.md b/.changeset/fix-pagelayout-overflow.md
new file mode 100644
index 00000000000..2869a2c3f2d
--- /dev/null
+++ b/.changeset/fix-pagelayout-overflow.md
@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+Fix PageLayout horizontal overflow by adding width constraint to ContentWrapper
diff --git a/package-lock.json b/package-lock.json
index a079a41e5c6..cf670f5700d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -81,7 +81,7 @@
         "react-dom": "^18.3.1"
       },
       "devDependencies": {
-        "@primer/react": "38.8.0",
+        "@primer/react": "38.9.0",
         "@primer/styled-react": "1.0.2",
         "@types/react": "^18.3.11",
         "@types/react-dom": "^18.3.0",
@@ -95,7 +95,7 @@
       "name": "example-nextjs",
       "version": "0.0.0",
       "dependencies": {
-        "@primer/react": "38.8.0",
+        "@primer/react": "38.9.0",
         "@primer/styled-react": "1.0.2",
         "next": "^16.1.5",
         "react": "^19.2.0",
@@ -138,7 +138,7 @@
       "version": "0.0.0",
       "dependencies": {
         "@primer/octicons-react": "^19.21.0",
-        "@primer/react": "38.8.0",
+        "@primer/react": "38.9.0",
         "@primer/styled-react": "1.0.2",
         "clsx": "^2.1.1",
         "next": "^16.1.5",
@@ -26883,7 +26883,7 @@
     },
     "packages/react": {
       "name": "@primer/react",
-      "version": "38.8.0",
+      "version": "38.9.0",
       "license": "MIT",
       "dependencies": {
         "@github/mini-throttle": "^2.1.1",
diff --git a/packages/react/src/PageLayout/PageLayout.module.css b/packages/react/src/PageLayout/PageLayout.module.css
index c9533a179f4..5466fce1d67 100644
--- a/packages/react/src/PageLayout/PageLayout.module.css
+++ b/packages/react/src/PageLayout/PageLayout.module.css
@@ -346,6 +346,7 @@
 
 .ContentWrapper {
   display: flex;
+  width: 100%;
 
   /* Hack to prevent overflowing content from pushing the pane region to the next line */
   min-width: 1px;