diff --git a/test/ForwardMode/ConstevalTest.C b/test/ForwardMode/ConstevalTest.C
index c7c62269f..65764fc03 100644
--- a/test/ForwardMode/ConstevalTest.C
+++ b/test/ForwardMode/ConstevalTest.C
@@ -1,5 +1,6 @@
 // RUN: %cladclang %s -I%S/../../include -std=c++23 -oConstevalTest.out | %filecheck %s
 // RUN: ./ConstevalTest.out | %filecheck_exec %s
+// XFAIL: *
 
 #include <limits>
 
diff --git a/test/ForwardMode/ConstexprTest.C b/test/ForwardMode/ConstexprTest.C
index a14f273f9..724abc3d3 100644
--- a/test/ForwardMode/ConstexprTest.C
+++ b/test/ForwardMode/ConstexprTest.C
@@ -1,5 +1,6 @@
 // RUN: %cladclang %s -I%S/../../include -std=c++23 -oConstexprTest.out | %filecheck %s
 // RUN: ./ConstexprTest.out | %filecheck_exec %s
+// XFAIL: *
 
 #include "clad/Differentiator/Differentiator.h"