diff --git a/glibc/sysdeps/unix/sysv/linux/riscv/swapcontext.S b/glibc/sysdeps/unix/sysv/linux/riscv/swapcontext.S
index 85e32484..c09ad21e 100644
--- a/glibc/sysdeps/unix/sysv/linux/riscv/swapcontext.S
+++ b/glibc/sysdeps/unix/sysv/linux/riscv/swapcontext.S
@@ -33,6 +33,7 @@ LEAF (__swapcontext)
 	REG_S	sp, ( 2 * SZREG + MCONTEXT_GREGS)(a0)
 	REG_S	s0, ( 8 * SZREG + MCONTEXT_GREGS)(a0)
 	REG_S	s1, ( 9 * SZREG + MCONTEXT_GREGS)(a0)
+	REG_S	x0, (10 * SZREG + MCONTEXT_GREGS)(a0)	/* return 0 */
 	REG_S	s2, (18 * SZREG + MCONTEXT_GREGS)(a0)
 	REG_S	s3, (19 * SZREG + MCONTEXT_GREGS)(a0)
 	REG_S	s4, (20 * SZREG + MCONTEXT_GREGS)(a0)