diff --git a/lib/fit4ruby/FitHeader.rb b/lib/fit4ruby/FitHeader.rb
index 4edbe0c..f453cf5 100644
--- a/lib/fit4ruby/FitHeader.rb
+++ b/lib/fit4ruby/FitHeader.rb
@@ -62,7 +62,7 @@ def dump
     end
 
     def has_crc?
-      header_size.snapshot == 14
+      header_size.snapshot == 14 && crc != 0x0000
     end
 
     def end_pos