diff --git a/browser/base/content/test/performance/browser_appmenu_reflows.js b/browser/base/content/test/performance/browser_appmenu_reflows.js
index 0ebd0a218825..253f7fb891a7 100644
--- a/browser/base/content/test/performance/browser_appmenu_reflows.js
+++ b/browser/base/content/test/performance/browser_appmenu_reflows.js
@@ -17,18 +17,6 @@ const EXPECTED_APPMENU_OPEN_REFLOWS = [
     ],
   },
 
-  {
-    stack: [
-      "get_alignmentPosition@chrome://global/content/bindings/popup.xml",
-      "adjustArrowPosition@chrome://global/content/bindings/popup.xml",
-      "onxblpopupshowing@chrome://global/content/bindings/popup.xml",
-      "openPopup@chrome://global/content/bindings/popup.xml",
-      "show/</<@chrome://browser/content/customizableui/panelUI.js",
-    ],
-
-    times: 2, // This number should only ever go down - never up.
-  },
-
   {
     stack: [
       "get_alignmentPosition@chrome://global/content/bindings/popup.xml",
@@ -51,7 +39,7 @@ const EXPECTED_APPMENU_OPEN_REFLOWS = [
       "openPopup@chrome://global/content/bindings/popup.xml",
     ],
 
-    times: 6, // This number should only ever go down - never up.
+    times: 7, // This number should only ever go down - never up.
   },
 ];
 
diff --git a/toolkit/content/tests/widgets/test_popupanchor.xul b/toolkit/content/tests/widgets/test_popupanchor.xul
index 172d98324661..ef8aefa968ff 100644
--- a/toolkit/content/tests/widgets/test_popupanchor.xul
+++ b/toolkit/content/tests/widgets/test_popupanchor.xul
@@ -92,7 +92,7 @@ function waitForPopupPositioned(actionFn, callback)
 {
   panel.addEventListener("popuppositioned", function listener() {
     panel.removeEventListener("popuppositioned", listener, false);
-    callback();
+    SimpleTest.executeSoon(callback);
   }, false);
   actionFn();
 }
@@ -173,26 +173,38 @@ var tests = [
   ['simpleMoveToAnchorHorizontal', 'middle', function(next) {
     openPopup("after_end", function() {
       isArrowPositionedOn("right");
-      panel.moveToAnchor(anchor, "after_end", 20, 0);
-      // the anchor and the panel should have moved 20px right without flipping.
-      isArrowPositionedOn("right", 20);
-      panel.moveToAnchor(anchor, "after_end", -20, 0);
-      // the anchor and the panel should have moved 20px left without flipping.
-      isArrowPositionedOn("right", -20);
-      next();
+      waitForPopupPositioned(
+       () => { panel.moveToAnchor(anchor, "after_end", 20, 0); },
+       () => {
+         // the anchor and the panel should have moved 20px right without flipping.
+         isArrowPositionedOn("right", 20);
+         waitForPopupPositioned(
+           () => { panel.moveToAnchor(anchor, "after_end", -20, 0);  },
+           () => {
+             // the anchor and the panel should have moved 20px left without flipping.
+             isArrowPositionedOn("right", -20);
+             next();
+          });
+       });
     });
   }],
 
   ['simpleMoveToAnchorVertical', 'middle', function(next) {
     openPopup("start_after", function() {
       isArrowPositionedOn("bottom");
-      panel.moveToAnchor(anchor, "start_after", 0, 20);
-      // the anchor and the panel should have moved 20px down without flipping.
-      isArrowPositionedOn("bottom", 20);
-      panel.moveToAnchor(anchor, "start_after", 0, -20);
-      // the anchor and the panel should have moved 20px up without flipping.
-      isArrowPositionedOn("bottom", -20);
-      next();
+      waitForPopupPositioned(
+       () => { panel.moveToAnchor(anchor, "start_after", 0, 20); },
+       () => {
+         // the anchor and the panel should have moved 20px down without flipping.
+         isArrowPositionedOn("bottom", 20);
+         waitForPopupPositioned(
+           () => { panel.moveToAnchor(anchor, "start_after", 0, -20) },
+           () => {
+             // the anchor and the panel should have moved 20px up without flipping.
+             isArrowPositionedOn("bottom", -20);
+             next();
+          });
+       });
     });
   }],
 
diff --git a/toolkit/content/tests/widgets/test_popupreflows.xul b/toolkit/content/tests/widgets/test_popupreflows.xul
index 817a43bbea7b..08aa2a3c7baa 100644
--- a/toolkit/content/tests/widgets/test_popupreflows.xul
+++ b/toolkit/content/tests/widgets/test_popupreflows.xul
@@ -100,7 +100,7 @@ addEventListener("load", function() {
   arrow.style.transition = "none";
 
   // and off we go...
-  countReflows(testSimplePanel, 1).then(SimpleTest.finish);
+  countReflows(testSimplePanel, 0).then(SimpleTest.finish);
 });
 ]]>
 </script>
diff --git a/toolkit/content/widgets/popup.xml b/toolkit/content/widgets/popup.xml
index 67d69b4a11d7..38fbf41841b7 100644
--- a/toolkit/content/widgets/popup.xml
+++ b/toolkit/content/widgets/popup.xml
@@ -492,8 +492,6 @@
         document.getAnonymousElementByAttribute(this, "anonid", "arrowbox")
                 .style.removeProperty("transform");
 
-        this.adjustArrowPosition();
-
         if (this.getAttribute("animate") != "false") {
           this.setAttribute("animate", "open");
           // the animating attribute prevents user interaction during transition