Index: trunk/Ohana/src/opihi/cmd.data/wd.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/wd.c	(revision 27435)
+++ trunk/Ohana/src/opihi/cmd.data/wd.c	(revision 38062)
@@ -81,14 +81,9 @@
   memcpy (temp_header.buffer, buf[0].header.buffer, temp_header.datasize);
 
-  if (temp_header.Naxes) {
-    // the inBlank value probably does not matter: temp_matrix is float, so nan is used
-    gfits_convert_format (&temp_header, &temp_matrix, outBitpix, outScale, outZero, 0xffff, outUnsign);
-  } else {
-    gfits_modify (&temp_header, "BITPIX", "%d", 1, outBitpix);
-    gfits_modify (&temp_header, "BSCALE", "%lf", 1, outScale);
-    gfits_modify (&temp_header, "BZERO",  "%lf", 1, outZero);
-    gfits_modify_alt (&temp_header, "UNSIGN", "%t", 1, outUnsign);
-  }
+  gfits_convert_format (&temp_header, &temp_matrix, outBitpix, outScale, outZero, 0xffff, outUnsign);
 
+  // Extend puts the output matrix in the first available non-PHU slot (ie, the last one)
+  // it updates NEXTEND and set EXTEND to TRUE, and modifies the PHU header (neither should happen)
+  // if those keywords do not exist...
   if (Extend) {
     Header Xhead;