--- a/dom/animation/test/mozilla/file_restyles.html
+++ b/dom/animation/test/mozilla/file_restyles.html
@@ -1283,31 +1283,24 @@ waitForAllPaints(() => {
 
     markers = await observeStyling(1);
     if (isServo) {
       // In Servo, we explicitly set important_rules_change flag to the element
       // in compute_style() during the initial normal traversal right after
       // re-attaching which leads to invoking a SequentialTask for
       // CascadeResults which ends up calling RequestRestyle(Standard). As a
       // result, the animation is restyled during a second animation restyle in
-      // the first frame. If we fix the behavior when we attach an orphaned
-      // element with script animations to a document so that it requests a
-      // layer restyle (bug 1388557) before fixing important_rules_change in
-      // compute_style() so that it no longer dispatches a needless standard
-      // restyle (bug 1388560), we should add a test case that fails if we
-      // continue to unnecessarily request a standard restyle.
+      // the first frame.
+      todo_is(markers.length, 1,
+              'Bug 1388560 We should observe one restyle in the first frame ' +
+              'right after re-attaching to the document');
+    } else {
       is(markers.length, 1,
          'We should observe one restyle in the first frame right after ' +
          're-attaching to the document');
-    } else {
-      // Bug 1388557: We should call RequestRestyle(Layer) when an element which
-      // has running script animations is attached to a document.
-      todo_is(markers.length, 1,
-              'Bug 1388557 We should observe one restyle in the first frame ' +
-              'right after re-attaching to the document');
     }
     markers = await observeStyling(5);
     is(markers.length, 5,
        'Animation on re-attached to the document begins to update style');
 
     await ensureElementRemoval(div);
   });
 

--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -1844,16 +1844,29 @@ Element::BindToTree(nsIDocument* aDocume
       nsIContent* parent = aParent;
       while (parent && !parent->IsRootOfNativeAnonymousSubtree()) {
         MOZ_ASSERT(parent->IsInNativeAnonymousSubtree());
         parent->SetFlags(NODE_IS_NATIVE_ANONYMOUS);
         parent = parent->GetParent();
       }
       MOZ_ASSERT(parent);
     }
+
+    if (MayHaveAnimations() &&
+        (pseudoType == CSSPseudoElementType::NotPseudo ||
+         pseudoType == CSSPseudoElementType::before ||
+         pseudoType == CSSPseudoElementType::after) &&
+        EffectSet::GetEffectSet(this, pseudoType)) {
+      if (nsPresContext* presContext = aDocument->GetPresContext()) {
+        presContext->EffectCompositor()->
+          RequestRestyle(this, pseudoType,
+                         EffectCompositor::RestyleType::Standard,
+                         EffectCompositor::CascadeLevel::Animations);
+      }
+    }
   }
 
   // XXXbz script execution during binding can trigger some of these
   // postcondition asserts....  But we do want that, since things will
   // generally be quite broken when that happens.
   MOZ_ASSERT(aDocument == GetUncomposedDoc(), "Bound to wrong document");
   MOZ_ASSERT(aParent == GetParent(), "Bound to wrong parent");
   MOZ_ASSERT(aBindingParent == GetBindingParent(),