diff --git a/cpp/src/sfntly/table/bitmap/bitmap_glyph_info.cc b/cpp/src/sfntly/table/bitmap/bitmap_glyph_info.cc
index ab9953b..a299b3e 100644
--- a/cpp/src/sfntly/table/bitmap/bitmap_glyph_info.cc
+++ b/cpp/src/sfntly/table/bitmap/bitmap_glyph_info.cc
@@ -52,7 +52,7 @@
 
 bool BitmapGlyphInfo::operator==(BitmapGlyphInfo* rhs) {
   if (rhs == NULL) {
-    return this == NULL;
+    return false;  // Well defined C++ code's this is always not null.
   }
   return (format_ == rhs->format() &&
           glyph_id_ == rhs->glyph_id() &&