diff --git a/xpfe/appshell/AppWindow.cpp b/xpfe/appshell/AppWindow.cpp
index f1730c059afa..7a38ad03d05e 100644
--- a/xpfe/appshell/AppWindow.cpp
+++ b/xpfe/appshell/AppWindow.cpp
@@ -1151,14 +1151,17 @@ static Maybe<int32_t> ReadIntAttribute(const Element& aElement,
 // to fit to the screen when staggering windows; if they're negative,
 // we use the window's current size instead.
 bool AppWindow::LoadPositionFromXUL(int32_t aSpecWidth, int32_t aSpecHeight) {
-  bool gotPosition = false;
-
   // if we're the hidden window, don't try to validate our size/position. We're
   // special.
   if (mIsHiddenWindow) {
     return false;
   }
 
+  // If we're not in the normal sizemode, don't move the window around.
+  if (mWindow->SizeMode() != nsSizeMode_Normal) {
+    return false;
+  }
+
   RefPtr<dom::Element> root = GetWindowDOMElement();
   NS_ENSURE_TRUE(root, false);
 
@@ -1184,6 +1187,7 @@ bool AppWindow::LoadPositionFromXUL(int32_t aSpecWidth, int32_t aSpecHeight) {
 
   // Obtain the position information from the <xul:window> element.
   DesktopIntPoint specPoint = curPoint;
+  bool gotPosition = false;
 
   // Also read lowercase screenx/y because the front-end sometimes sets these
   // via setAttribute on HTML documents like about:blank, and stuff gets
@@ -1219,7 +1223,6 @@ bool AppWindow::LoadPositionFromXUL(int32_t aSpecWidth, int32_t aSpecHeight) {
   if (specPoint != curPoint) {
     SetPositionDesktopPix(specPoint.x, specPoint.y);
   }
-
   return gotPosition;
 }