diff --git a/libraries/AP_Filesystem/posix_compat.h b/libraries/AP_Filesystem/posix_compat.h
index c899d81332..4ccf56b5c5 100644
--- a/libraries/AP_Filesystem/posix_compat.h
+++ b/libraries/AP_Filesystem/posix_compat.h
@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {