diff --git a/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibRuntimeXF86.cpp b/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibRuntimeXF86.cpp
index 8a9d15c0..260ebc5c 100644
--- a/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibRuntimeXF86.cpp
+++ b/src/VBox/Additions/common/VBoxGuest/lib/VBoxGuestR3LibRuntimeXF86.cpp
@@ -46,6 +46,9 @@
 #if defined(VBOX_VBGLR3_XFREE86)
 extern "C" {
 # define XFree86LOADER
+# ifdef RT_GNUC_PREREQ(13,0) /* cmath gets dragged in and the c++/13/cmath header is allergic to -ffreestanding.  */
+#  define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
+# endif
 # include <xf86_ansic.h>
 # undef size_t
 }
diff --git a/src/libs/dxvk-native-1.9.2a/src/util/util_matrix.cpp b/src/libs/dxvk-native-1.9.2a/src/util/util_matrix.cpp
index 2c5e9314..64890169 100644
--- a/src/libs/dxvk-native-1.9.2a/src/util/util_matrix.cpp
+++ b/src/libs/dxvk-native-1.9.2a/src/util/util_matrix.cpp
@@ -1,3 +1,5 @@
+#include <cstdint>
+
 #include "util_matrix.h"
 
 namespace dxvk {
diff --git a/src/libs/dxvk-native-1.9.2a/src/util/util_vector.h b/src/libs/dxvk-native-1.9.2a/src/util/util_vector.h
index 77cdf294..9dcb4bf9 100644
--- a/src/libs/dxvk-native-1.9.2a/src/util/util_vector.h
+++ b/src/libs/dxvk-native-1.9.2a/src/util/util_vector.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <iostream>
 
 #include "util_bit.h"