diff --git a/taglib/mpeg/id3v2/id3v2framefactory.cpp b/taglib/mpeg/id3v2/id3v2framefactory.cpp
index 7e2e98a8..bba2985c 100644
--- a/taglib/mpeg/id3v2/id3v2framefactory.cpp
+++ b/taglib/mpeg/id3v2/id3v2framefactory.cpp
@@ -99,7 +99,7 @@ Frame *FrameFactory::createFrame(const ByteVector &origData, Header *tagHeader)
   // A quick sanity check -- make sure that the frameID is 4 uppercase Latin1
   // characters.  Also make sure that there is data in the frame.
 
-  if(!frameID.size() == (version < 3 ? 3 : 4) ||
+  if(frameID.size() != (version < 3 ? 3 : 4) ||
      header->frameSize() <= uint(header->dataLengthIndicator() ? 4 : 0) ||
      header->frameSize() > data.size())
   {