diff -uNr strace-5.2/stage_output.c strace-5.2.mod/stage_output.c
--- strace-5.2/stage_output.c	2019-07-10 19:12:44.000000000 +0300
+++ strace-5.2.mod/stage_output.c	2019-07-14 20:45:29.066735864 +0300
@@ -54,7 +54,7 @@
 	tcp->real_outf = NULL;
 	if (tcp->memfptr) {
 		if (publish)
-			fputs_unlocked(tcp->memfptr, tcp->outf);
+			fputs(tcp->memfptr, tcp->outf);
 		else
 			debug_msg("syscall output dropped: %s", tcp->memfptr);
 		free(tcp->memfptr);
diff -uNr strace-5.2/strace.c strace-5.2.mod/strace.c
--- strace-5.2/strace.c	2019-07-10 19:12:44.000000000 +0300
+++ strace-5.2.mod/strace.c	2019-07-14 20:45:05.963303029 +0300
@@ -525,15 +525,11 @@
 	va_end(args);
 }
 
-#ifndef HAVE_FPUTS_UNLOCKED
-# define fputs_unlocked fputs
-#endif
-
 void
 tprints(const char *str)
 {
 	if (current_tcp) {
-		int n = fputs_unlocked(str, current_tcp->outf);
+		int n = fputs(str, current_tcp->outf);
 		if (n >= 0) {
 			current_tcp->curcol += strlen(str);
 			return;