diff --git a/include/common/buf.h b/include/common/buf.h
index d39de71..cc670bf 100644
--- a/include/common/buf.h
+++ b/include/common/buf.h
@@ -30,6 +30,7 @@
 
 #include <stdint.h>
 #include <string.h>
+#include <unistd.h>
 
 /* Structure defining a buffer's head */
 struct buffer {
diff --git a/include/common/ist.h b/include/common/ist.h
index 7c60c68..cfab1e3 100644
--- a/include/common/ist.h
+++ b/include/common/ist.h
@@ -30,6 +30,7 @@
 
 #include <ctype.h>
 #include <string.h>
+#include <unistd.h>
 
 #include <common/config.h>
 
diff --git a/include/common/memory.h b/include/common/memory.h
index b854ebb..57d6ba6 100644
--- a/include/common/memory.h
+++ b/include/common/memory.h
@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdint.h>
+#include <unistd.h>
 
 #include <common/config.h>
 #include <common/mini-clist.h>