diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index a0765e7ed6c7..b0255cbf3b76 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -46,7 +46,10 @@ extern char * strstr(const char * s1, const char *s2);
 #endif
 
 #ifdef CONFIG_KERNEL_XZ
+/* Prevent KASAN override of string helpers in decompressor */
+#undef memmove
 #define memmove memmove
+#undef memcpy
 #define memcpy memcpy
 #include "../../../../lib/decompress_unxz.c"
 #endif