diff --git a/core/runtime/os_specific_wasi.odin b/core/runtime/os_specific_wasi.odin
new file mode 100644
index 000000000..94cf4c85c
--- /dev/null
+++ b/core/runtime/os_specific_wasi.odin
@@ -0,0 +1,10 @@
+//+build wasi
+package runtime
+
+import "core:sys/wasm/wasi"
+
+_os_write :: proc "contextless" (data: []byte) -> (int, _OS_Errno) {
+	data := (wasi.ciovec_t)(data)
+	n, err := wasi.fd_write(1, &data, 1)
+	return int(n), _OS_Errno(err)
+}