--- ray/src/rt/rc2.c	2017/02/07 16:48:14	2.22
+++ ray/src/rt/rc2.c	2019/09/04 20:19:51	2.24
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rc2.c,v 2.22 2017/02/07 16:48:14 greg Exp $";
+static const char RCSid[] = "$Id: rc2.c,v 2.24 2019/09/04 20:19:51 greg Exp $";
 #endif
 /*
  * Accumulate ray contributions for a set of materials
@@ -116,6 +116,8 @@ printheader(FILE *fout, const char *info)
 	fputs("NCOMP=3\n", fout);		/* always RGB */
 	if (info != NULL)			/* add extra info if given */
 		fputs(info, fout);
+	if ((outfmt == 'f') | (outfmt == 'd'))
+		fputendian(fout);
 	fputformat(formstr(outfmt), fout);
 	fputc('\n', fout);			/* empty line ends header */
 }
@@ -146,6 +148,9 @@ getostream(const char *ospec, const char *mname, int b
 		if (!noopen & !using_stdout) {
 			if (outfmt != 'a')
 				SET_FILE_BINARY(stdout);
+#ifdef getc_unlocked
+			flockfile(stdout);	/* avoid lock/unlock overhead */
+#endif
 			if (header) {
 				cp = info;
 				if (yres > 0) {
@@ -162,9 +167,6 @@ getostream(const char *ospec, const char *mname, int b
 			if (waitflush > 0)
 				fflush(stdout);
 			stdos.xr = xres; stdos.yr = yres;
-#ifdef getc_unlocked
-			flockfile(stdout);	/* avoid lock/unlock overhead */
-#endif
 			using_stdout = 1;
 		}
 		stdos.ofp = stdout;