diff --git a/BasiliskII/src/Unix/vm_alloc.h b/BasiliskII/src/Unix/vm_alloc.h
index 4ad82a53..336ba4c0 100644
--- a/BasiliskII/src/Unix/vm_alloc.h
+++ b/BasiliskII/src/Unix/vm_alloc.h
@@ -25,6 +25,7 @@
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#include <sys/types.h>
 #endif
 #ifdef HAVE_SYS_MMAN_H
 #include <sys/mman.h>