diff --git a/parser/html/javasrc/TreeBuilder.java b/parser/html/javasrc/TreeBuilder.java
index 2e7cf6196ee9..9b8e8423fc8f 100644
--- a/parser/html/javasrc/TreeBuilder.java
+++ b/parser/html/javasrc/TreeBuilder.java
@@ -1953,6 +1953,7 @@ public abstract class TreeBuilder<T> implements TokenHandler,
                                 if (TreeBuilder.NOT_FOUND_ON_STACK != findLastInScope("nobr")) {
                                     err("\u201Cnobr\u201D start tag seen when there was an open \u201Cnobr\u201D element in scope.");
                                     adoptionAgencyEndTag("nobr");
+                                    reconstructTheActiveFormattingElements();
                                 }
                                 appendToCurrentNodeAndPushFormattingElementMayFoster(
                                         elementName,
diff --git a/parser/html/nsHtml5TreeBuilder.cpp b/parser/html/nsHtml5TreeBuilder.cpp
index 2874eae09fe9..965618f3afbc 100644
--- a/parser/html/nsHtml5TreeBuilder.cpp
+++ b/parser/html/nsHtml5TreeBuilder.cpp
@@ -1038,6 +1038,7 @@ nsHtml5TreeBuilder::startTag(nsHtml5ElementName* elementName, nsHtml5HtmlAttribu
               if (NS_HTML5TREE_BUILDER_NOT_FOUND_ON_STACK != findLastInScope(nsHtml5Atoms::nobr)) {
 
                 adoptionAgencyEndTag(nsHtml5Atoms::nobr);
+                reconstructTheActiveFormattingElements();
               }
               appendToCurrentNodeAndPushFormattingElementMayFoster(elementName, attributes);
               attributes = nsnull;