diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index f9c4452..1e6aed1 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -1789,6 +1789,11 @@
   registry->RegisterBooleanPref(prefs::kOopPrintDriversAllowedByPolicy, true);
 #endif
 
+#if BUILDFLAG(ENABLE_PDF)
+  registry->RegisterBooleanPref(prefs::kPdfViewerOutOfProcessIframeEnabled,
+                                true);
+#endif  // BUILDFLAG(ENABLE_PDF)
+
 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN)
   registry->RegisterBooleanPref(prefs::kChromeForTestingAllowed, true);
 #endif