--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -9891,33 +9891,33 @@ nsCSSFrameConstructor::CreateNeededPseud
   nsIFrame* aParentFrame)
 {
   const ParentType ourParentType = GetParentType(aParentFrame);
   if (!IsRubyParentType(ourParentType) ||
       aItems.AllWantParentType(ourParentType)) {
     return;
   }
 
-  nsStyleContext* parentStyle = aParentFrame->StyleContext();
-  if (!parentStyle->GetPseudo()) {
-    // Normally, pseudo frames start from and end at some elements,
+  if (!IsRubyPseudo(aParentFrame)) {
+    // Normally, ruby pseudo frames start from and end at some elements,
     // which means they don't have leading and trailing whitespaces at
     // all.  But there are two cases where they do actually have leading
     // or trailing whitespaces:
     // 1. It is an inter-segment whitespace which in an individual ruby
     //    base container.
     // 2. The pseudo frame starts from or ends at consecutive inline
     //    content, which is not pure whitespace, but includes some.
     // In either case, the whitespaces are not the leading or trailing
     // whitespaces defined in the spec, and thus should not be trimmed.
     TrimLeadingAndTrailingWhitespaces(aState, aItems);
   }
 
   FCItemIterator iter(aItems);
   nsIContent* parentContent = aParentFrame->GetContent();
+  nsStyleContext* parentStyle = aParentFrame->StyleContext();
   while (!iter.IsDone()) {
     if (!iter.SkipItemsWantingParentType(ourParentType)) {
       if (ourParentType == eTypeRuby) {
         WrapItemsInPseudoRubyLevelContainer(aState, iter, parentStyle,
                                             parentContent);
       } else {
         WrapItemsInPseudoRubyLeafBox(iter, parentStyle, parentContent);
       }