diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index ac24077abd02..e0870fb7d719 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2905,6 +2905,9 @@ pref("svg.disabled", false);
 // Override default dom.ipc.processCount for some remote content process types.
 pref("dom.ipc.processCount.webLargeAllocation", 2);
 
+// Enable the Large-Allocation header
+pref("dom.largeAllocationHeader.enabled", true);
+
 // Pref to control whether we use separate content processes for top-level load
 // of file:// URIs.
 #if defined(NIGHTLY_BUILD)