diff --git a/gprof/ChangeLog b/gprof/ChangeLog
index 58503656d7..50eea2da5d 100644
--- a/gprof/ChangeLog
+++ b/gprof/ChangeLog
@@ -1,3 +1,7 @@
+2001-01-27  Michael Sokolov  <msokolov@ivan.Harhan.ORG>
+
+	* basic_blocks.c: #include <unistd.h> only if it exists.
+
 2000-11-06  Nick Clifton  <nickc@redhat.com>
 
 	* gprof.texi: Add GNU Free Documentation License.
diff --git a/gprof/basic_blocks.c b/gprof/basic_blocks.c
index 926743ff05..fa6afe7a0d 100644
--- a/gprof/basic_blocks.c
+++ b/gprof/basic_blocks.c
@@ -22,7 +22,6 @@
    02111-1307, USA.  */
 
 #include <stdio.h>
-#include <unistd.h>
 #include "basic_blocks.h"
 #include "corefile.h"
 #include "gmon_io.h"
@@ -31,6 +30,9 @@
 #include "libiberty.h"
 #include "source.h"
 #include "sym_ids.h"
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 
 /* Default option values:  */
 bool bb_annotate_all_lines = FALSE;