diff --git a/layout/base/nsPresContext.cpp b/layout/base/nsPresContext.cpp
index 679dd6dcbe07..e159edba100c 100644
--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -269,11 +269,13 @@ static const char* gExactCallbackPrefs[] = {
     "nglayout.debug.paint_flashing",
     "nglayout.debug.paint_flashing_chrome",
     "intl.accept_languages",
+    "dom.meta-viewport.enabled",
     nullptr,
 };
 
 static const char* gPrefixCallbackPrefs[] = {
-    "font.", "browser.display.", "bidi.", "gfx.font_rendering.", nullptr,
+    "font.", "browser.display.",    "browser.viewport.",
+    "bidi.", "gfx.font_rendering.", nullptr,
 };
 
 void nsPresContext::Destroy() {
@@ -497,6 +499,15 @@ void nsPresContext::PreferenceChanged(const char* aPrefName) {
     }
     return;
   }
+
+  if (StringBeginsWith(prefName, "browser.viewport."_ns) ||
+      StringBeginsWith(prefName, "font.size.inflation."_ns) ||
+      prefName.EqualsLiteral("dom.meta-viewport.enabled")) {
+    if (mPresShell) {
+      mPresShell->MaybeReflowForInflationScreenSizeChange();
+    }
+  }
+
   
   
   if (prefName.EqualsLiteral("layout.css.prefers-contrast.enabled") ||