diff --git a/dlib/simd/simd4i.h b/dlib/simd/simd4i.h
index c59e81acf..d32bc1c9a 100644
--- a/dlib/simd/simd4i.h
+++ b/dlib/simd/simd4i.h
@@ -4,7 +4,7 @@
 #define DLIB_sIMD4I_H__
 
 #include "simd_check.h"
-#include "dlib/uintn.h"
+#include "../uintn.h"
 
 namespace dlib
 {