diff --git a/python/obitools3/format/header.pyx b/python/obitools3/format/header.pyx
index 9e24106..8b15d8c 100755
--- a/python/obitools3/format/header.pyx
+++ b/python/obitools3/format/header.pyx
@@ -6,7 +6,7 @@ from obitools3.dms.capi.obiview cimport NUC_SEQUENCE_COLUMN, \
                                         QUALITY_COLUMN, \
                                         COUNT_COLUMN
 
-from obitools3.utils cimport str2bytes
+from obitools3.utils cimport str2bytes, bytes2str_object
 from obitools3.dms.column.column cimport Column_line
 
 
@@ -63,7 +63,7 @@ cdef class HeaderFormat:
                     if type(value) == Column_line:
                         value = value.bytes()
                     else:
-                        value = str2bytes(str(value))   # TODO ugly but how else?
+                        value = str2bytes(str(bytes2str_object(value))) # genius programming
                 if value is not None:
                     lines.append(k + b"=" + value + b";")