diff --git a/dom/base/nsPlainTextSerializer.cpp b/dom/base/nsPlainTextSerializer.cpp
index 5ae4b3b78b81..be3a3b26e96c 100644
--- a/dom/base/nsPlainTextSerializer.cpp
+++ b/dom/base/nsPlainTextSerializer.cpp
@@ -1774,7 +1774,8 @@ nsPlainTextSerializer::IsElementPreformatted(Element* aElement)
     const nsStyleText* textStyle = styleContext->StyleText();
     return textStyle->WhiteSpaceOrNewlineIsSignificant();
   }
-  return false;
+  // Fall back to looking at the tag, in case there is no style information.
+  return GetIdForContent(aElement) == nsGkAtoms::pre;
 }
 
 /**
diff --git a/dom/base/test/TestPlainTextSerializer.cpp b/dom/base/test/TestPlainTextSerializer.cpp
index be77795361e3..7be9bce0fda0 100644
--- a/dom/base/test/TestPlainTextSerializer.cpp
+++ b/dom/base/test/TestPlainTextSerializer.cpp
@@ -114,6 +114,29 @@ TestPrettyPrintedHtml()
   return NS_OK;
 }
 
+nsresult
+TestPreElement()
+{
+  nsString test;
+  test.AppendLiteral(
+    "<html>" NS_LINEBREAK
+    "<body>" NS_LINEBREAK
+    "<pre>" NS_LINEBREAK
+    "  first" NS_LINEBREAK
+    "  second" NS_LINEBREAK
+    "</pre>" NS_LINEBREAK
+    "</body>" NS_LINEBREAK "</html>");
+
+  ConvertBufToPlainText(test, 0);
+  if (!test.EqualsLiteral("  first" NS_LINEBREAK "  second" NS_LINEBREAK NS_LINEBREAK)) {
+    fail("Wrong prettyprinted html to text serialization");
+    return NS_ERROR_FAILURE;
+  }
+
+  passed("prettyprinted HTML to text serialization test");
+  return NS_OK;
+}
+
 nsresult
 TestPlainTextSerializer()
 {
@@ -137,6 +160,9 @@ TestPlainTextSerializer()
   rv = TestPrettyPrintedHtml();
   NS_ENSURE_SUCCESS(rv, rv);
 
+  rv = TestPreElement();
+  NS_ENSURE_SUCCESS(rv, rv);
+
   // Add new tests here...
   return NS_OK;
 }
