diff --git a/contrib/pzstd/Options.cpp b/contrib/pzstd/Options.cpp
index 18c069eae..0b1403354 100644
--- a/contrib/pzstd/Options.cpp
+++ b/contrib/pzstd/Options.cpp
@@ -22,19 +22,13 @@
     defined(__CYGWIN__)
 #include <io.h> /* _isatty */
 #define IS_CONSOLE(stdStream) _isatty(_fileno(stdStream))
-#else
-#if defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) ||                      \
-    defined(_POSIX_SOURCE) ||                                                  \
-    (defined(__APPLE__) &&                                                     \
-     defined(                                                                  \
-         __MACH__)) /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ \
-                       */
+#elif defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) || defined(_POSIX_SOURCE) || (defined(__APPLE__) && defined(__MACH__)) || \
+      defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)  /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ */
 #include <unistd.h> /* isatty */
 #define IS_CONSOLE(stdStream) isatty(fileno(stdStream))
 #else
 #define IS_CONSOLE(stdStream) 0
 #endif
-#endif
 
 namespace pzstd {
 
diff --git a/programs/util.h b/programs/util.h
index 3d5c44642..0fa70577a 100644
--- a/programs/util.h
+++ b/programs/util.h
@@ -98,7 +98,7 @@ extern "C" {
 #    define SET_HIGH_PRIORITY /* disabled */
 #  endif
 #  define UTIL_sleep(s) sleep(s)
-#  if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 199309L)
+#  if defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || (defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 199309L))
 #      define UTIL_sleepMilli(milli) { struct timespec t; t.tv_sec=0; t.tv_nsec=milli*1000000ULL; nanosleep(&t, NULL); }
 #  else
 #      define UTIL_sleepMilli(milli) /* disabled */
diff --git a/programs/zstdcli.c b/programs/zstdcli.c
index 7ffb0bb62..561730a5f 100644
--- a/programs/zstdcli.c
+++ b/programs/zstdcli.c
@@ -43,7 +43,8 @@
 #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
 #  include <io.h>       /* _isatty */
 #  define IS_CONSOLE(stdStream) _isatty(_fileno(stdStream))
-#elif defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) || defined(_POSIX_SOURCE) || (defined(__APPLE__) && defined(__MACH__))  /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ */
+#elif defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) || defined(_POSIX_SOURCE) || (defined(__APPLE__) && defined(__MACH__)) || \
+      defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)  /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ */
 #  include <unistd.h>   /* isatty */
 #  define IS_CONSOLE(stdStream) isatty(fileno(stdStream))
 #else