diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 67322f878e0d..f704c8dd57e0 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -43,6 +43,7 @@
 #ifndef __ASSEMBLY__
 
 extern long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE / sizeof(long)];
+extern unsigned long spin_shadow_stack;
 
 #include <asm/processor.h>
 #include <asm/csr.h>