diff --git a/lib/std/os/linux/riscv32.zig b/lib/std/os/linux/riscv32.zig
index ceabe30a87116d5e1ae8114d6f5751c4e15139f4..cb1243a0ca892ab9a39226e11bc645c15704d22f 100644
--- a/lib/std/os/linux/riscv32.zig
+++ b/lib/std/os/linux/riscv32.zig
@@ -116,6 +116,7 @@ pub fn clone() callconv(.naked) u32 {
     // syscall(SYS_clone, flags, stack, ptid, tls, ctid)
     //         a7         a0,    a1,    a2,   a3,  a4
     asm volatile (
+        \\    andi a1, a1, -16
         \\    # Save func and arg to stack
         \\    addi a1, a1, -8
         \\    sw a0, 0(a1)
diff --git a/lib/std/os/linux/riscv64.zig b/lib/std/os/linux/riscv64.zig
index 41dabbb47216c84af9e43ecbe8c89853aee7c584..accde6d5e6a06db1cfcd4be94f2165ff2c2b6cc4 100644
--- a/lib/std/os/linux/riscv64.zig
+++ b/lib/std/os/linux/riscv64.zig
@@ -116,6 +116,7 @@ pub fn clone() callconv(.naked) u64 {
     // syscall(SYS_clone, flags, stack, ptid, tls, ctid)
     //         a7         a0,    a1,    a2,   a3,  a4
     asm volatile (
+        \\    andi a1, a1, -16
         \\    # Save func and arg to stack
         \\    addi a1, a1, -16
         \\    sd a0, 0(a1)