diff --git a/htmlparser/src/nsViewSourceHTML.cpp b/htmlparser/src/nsViewSourceHTML.cpp
index fabbc736f769..a12abf2d688a 100644
--- a/htmlparser/src/nsViewSourceHTML.cpp
+++ b/htmlparser/src/nsViewSourceHTML.cpp
@@ -644,7 +644,7 @@ nsresult WriteText(const nsString& aTextString,nsIContentSink& aSink,PRBool aPre
           }
           theSpaces+=8;
           theOffset++;
-          theTextOffset=theOffset+1;
+          theTextOffset=theOffset;
         }
         break;
 
diff --git a/parser/htmlparser/src/nsViewSourceHTML.cpp b/parser/htmlparser/src/nsViewSourceHTML.cpp
index fabbc736f769..a12abf2d688a 100644
--- a/parser/htmlparser/src/nsViewSourceHTML.cpp
+++ b/parser/htmlparser/src/nsViewSourceHTML.cpp
@@ -644,7 +644,7 @@ nsresult WriteText(const nsString& aTextString,nsIContentSink& aSink,PRBool aPre
           }
           theSpaces+=8;
           theOffset++;
-          theTextOffset=theOffset+1;
+          theTextOffset=theOffset;
         }
         break;