diff --git a/parser/htmlparser/nsIDTD.h b/parser/htmlparser/nsIDTD.h
index a47938befa5a..8f1d152ab4b3 100644
--- a/parser/htmlparser/nsIDTD.h
+++ b/parser/htmlparser/nsIDTD.h
@@ -34,9 +34,7 @@
 
 enum eAutoDetectResult {
   eUnknownDetect,
-  eValidDetect,
   ePrimaryDetect,
-  eInvalidDetect
 };
 
 enum nsDTDMode {
diff --git a/parser/htmlparser/nsParser.cpp b/parser/htmlparser/nsParser.cpp
index aab34524a78a..22358e3a95ec 100644
--- a/parser/htmlparser/nsParser.cpp
+++ b/parser/htmlparser/nsParser.cpp
@@ -1270,14 +1270,6 @@ nsresult nsParser::OnDataAvailable(nsIRequest* request,
   if (theContext) {
     theContext->mStreamListenerState = eOnDataAvail;
 
-    if (eInvalidDetect == theContext->mAutoDetectStatus) {
-      if (theContext->mScanner) {
-        nsScannerIterator iter;
-        theContext->mScanner->EndReading(iter);
-        theContext->mScanner->SetPosition(iter, true);
-      }
-    }
-
     uint32_t totalRead;
     ParserWriteStruct pws;
     pws.mNeedCharsetCheck = true;