diff --git a/arch/um/include/asm/xor.h b/arch/um/include/asm/xor.h
index f512704a9ec7..22b39de73c24 100644
--- a/arch/um/include/asm/xor.h
+++ b/arch/um/include/asm/xor.h
@@ -4,8 +4,10 @@
 
 #ifdef CONFIG_64BIT
 #undef CONFIG_X86_32
+#define TT_CPU_INF_XOR_DEFAULT (AVX_SELECT(&xor_block_sse_pf64))
 #else
 #define CONFIG_X86_32 1
+#define TT_CPU_INF_XOR_DEFAULT (AVX_SELECT(&xor_block_8regs))
 #endif
 
 #include <asm/cpufeature.h>
@@ -16,7 +18,7 @@
 #undef XOR_SELECT_TEMPLATE
 /* pick an arbitrary one - measuring isn't possible with inf-cpu */
 #define XOR_SELECT_TEMPLATE(x)	\
-	(time_travel_mode == TT_MODE_INFCPU ? &xor_block_8regs : NULL)
+	(time_travel_mode == TT_MODE_INFCPU ? TT_CPU_INF_XOR_DEFAULT : x))
 #endif
 
 #endif