diff --git a/blahtexml/Source/main.cpp b/blahtexml/Source/main.cpp
index f07aa0e..c6f77a4 100644
--- a/blahtexml/Source/main.cpp
+++ b/blahtexml/Source/main.cpp
@@ -22,6 +22,7 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 #include <iostream>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <sstream>
 #include <stdexcept>
 
diff --git a/blahtexml/Source/mainPng.cpp b/blahtexml/Source/mainPng.cpp
index 5183d1b..4be5a31 100644
--- a/blahtexml/Source/mainPng.cpp
+++ b/blahtexml/Source/mainPng.cpp
@@ -27,7 +27,7 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 #include <stdio.h>
 #include <stdlib.h>
 #include <sstream>
-
+#include <unistd.h>
 
 using namespace std;
 using namespace blahtex;