diff --git a/src/flarq-src/flarq.cxx b/src/flarq-src/flarq.cxx
index 1cde93cf..01cb93eb 100644
--- a/src/flarq-src/flarq.cxx
+++ b/src/flarq-src/flarq.cxx
@@ -21,7 +21,7 @@
 // ----------------------------------------------------------------------------
 
 #include <config.h>
-
+#include <unistd.h>
 #include <stdlib.h>
 #include <iostream>
 #include <fstream>
diff --git a/src/logger/rx_extract.cxx b/src/logger/rx_extract.cxx
index 661f991c..35e4ba8e 100644
--- a/src/logger/rx_extract.cxx
+++ b/src/logger/rx_extract.cxx
@@ -21,6 +21,7 @@
 
 #include <config.h>
 
+#include <unistd.h>
 #include <iostream>
 #include <fstream>
 #include <string>
diff --git a/src/wefax/wefax-pic.cxx b/src/wefax/wefax-pic.cxx
index 386f13ee..db0ea507 100644
--- a/src/wefax/wefax-pic.cxx
+++ b/src/wefax/wefax-pic.cxx
@@ -30,7 +30,9 @@
 #include <sstream>
 #include <iomanip>
 
+
 #include <time.h>
+#include <unistd.h>
 
 #include <FL/Fl_Widget.H>
 #include <FL/Fl_Button.H>
diff --git a/src/wefax/wefax.cxx b/src/wefax/wefax.cxx
index bce1b7f7..ec998b97 100644
--- a/src/wefax/wefax.cxx
+++ b/src/wefax/wefax.cxx
@@ -25,6 +25,7 @@
 
 #include <config.h>
 
+#include <unistd.h>
 #include <cstdlib>
 #include <sstream>
 #include <iostream>