diff --git a/configure.ac b/configure.ac
index 5dc1c63..32496f6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -157,7 +157,7 @@ AC_CHECK_HEADERS([sys/socket.h linux/types.h linux/irda.h], , , [
 # Checks for header files.
 AC_CHECK_HEADERS([linux/serial.h])
 AC_CHECK_HEADERS([IOKit/serial/ioss.h])
-AC_CHECK_HEADERS([getopt.h])
+AC_CHECK_HEADERS([unistd.h getopt.h])
 AC_CHECK_HEADERS([sys/param.h])
 AC_CHECK_HEADERS([pthread.h])
 AC_CHECK_HEADERS([mach/mach_time.h])
diff --git a/examples/dctool.c b/examples/dctool.c
index 3104bc4..9d3f74b 100644
--- a/examples/dctool.c
+++ b/examples/dctool.c
@@ -24,10 +24,12 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
 #include <stdio.h>
 #include <signal.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_download.c b/examples/dctool_download.c
index 2a39f5f..04aedcf 100644
--- a/examples/dctool_download.c
+++ b/examples/dctool_download.c
@@ -24,9 +24,11 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_dump.c b/examples/dctool_dump.c
index 6aa2e4a..966edbc 100644
--- a/examples/dctool_dump.c
+++ b/examples/dctool_dump.c
@@ -24,9 +24,11 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_fwupdate.c b/examples/dctool_fwupdate.c
index 596ccb1..4395c39 100644
--- a/examples/dctool_fwupdate.c
+++ b/examples/dctool_fwupdate.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_help.c b/examples/dctool_help.c
index 2848c24..33ea0a5 100644
--- a/examples/dctool_help.c
+++ b/examples/dctool_help.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_list.c b/examples/dctool_list.c
index 89e5386..bc70d13 100644
--- a/examples/dctool_list.c
+++ b/examples/dctool_list.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_parse.c b/examples/dctool_parse.c
index 6b7da08..b898b5c 100644
--- a/examples/dctool_parse.c
+++ b/examples/dctool_parse.c
@@ -24,9 +24,11 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_read.c b/examples/dctool_read.c
index 2a9bf18..31ffc8d 100644
--- a/examples/dctool_read.c
+++ b/examples/dctool_read.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_scan.c b/examples/dctool_scan.c
index 868a9a7..378a8f8 100644
--- a/examples/dctool_scan.c
+++ b/examples/dctool_scan.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_timesync.c b/examples/dctool_timesync.c
index 35647b1..eeff0bb 100644
--- a/examples/dctool_timesync.c
+++ b/examples/dctool_timesync.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_version.c b/examples/dctool_version.c
index deb0702..dbb7a40 100644
--- a/examples/dctool_version.c
+++ b/examples/dctool_version.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
diff --git a/examples/dctool_write.c b/examples/dctool_write.c
index fc76c78..04db198 100644
--- a/examples/dctool_write.c
+++ b/examples/dctool_write.c
@@ -24,8 +24,10 @@
 #endif
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif