diff --git a/src/graphics/GraphicsConverter.h b/src/graphics/GraphicsConverter.h
index 536a84013d..51bac226e3 100644
--- a/src/graphics/GraphicsConverter.h
+++ b/src/graphics/GraphicsConverter.h
@@ -25,6 +25,7 @@
 #include <boost/utility.hpp>
 #include <sigc++/signal_system.h>
 #include <list>
+#include <sys/types.h> // needed for pid_t
 
 #ifdef __GNUG__
 #pragma interface
diff --git a/src/support/forkedcontr.h b/src/support/forkedcontr.h
index 967ecc9c24..96db3f9655 100644
--- a/src/support/forkedcontr.h
+++ b/src/support/forkedcontr.h
@@ -18,6 +18,7 @@
 #include <vector>
 #include "LString.h"
 #include <sigc++/signal_system.h>
+#include <sys/types.h> // needed for pid_t
 
 #ifdef __GNUG__
 #pragma interface