diff --git a/compat/mimalloc/alloc.c b/compat/mimalloc/alloc.c
index cd711e73f5..c0ada97c90 100644
--- a/compat/mimalloc/alloc.c
+++ b/compat/mimalloc/alloc.c
@@ -17,7 +17,6 @@ terms of the MIT license. A copy of the license can be found in the file
 #include <stdlib.h>      // malloc, abort
 
 #define MI_IN_ALLOC_C
-#include "alloc-override.c"
 #include "free.c"
 #undef MI_IN_ALLOC_C
 
diff --git a/compat/mimalloc/mimalloc.h b/compat/mimalloc/mimalloc.h
index 174d9a34c9..6a926d1c80 100644
--- a/compat/mimalloc/mimalloc.h
+++ b/compat/mimalloc/mimalloc.h
@@ -95,7 +95,8 @@ terms of the MIT license. A copy of the license can be found in the file
 // Includes
 // ------------------------------------------------------
 
-#include <stddef.h>     // size_t
+#include "compat/posix.h"
+
 #include <stdbool.h>    // bool
 #include <stdint.h>     // INTPTR_MAX