diff --git a/renderdoc/os/posix/apple/apple_hook.cpp b/renderdoc/os/posix/apple/apple_hook.cpp
index 7f8c4fb40..a8f3d6e6c 100644
--- a/renderdoc/os/posix/apple/apple_hook.cpp
+++ b/renderdoc/os/posix/apple/apple_hook.cpp
@@ -25,6 +25,7 @@
 #include "os/posix/posix_hook.h"
 
 #include <dlfcn.h>
+#include <stddef.h>
 
 void PosixHookInit()
 {
@@ -37,4 +38,4 @@ bool PosixHookDetect(const char *identifier)
 
 void PosixHookLibrary(const char *name, dlopenCallback cb)
 {
-}
\ No newline at end of file
+}