diff --git a/src/wasi.rs b/src/wasi.rs
index 5234805731f8d..1a855e0e0fe77 100644
--- a/src/wasi.rs
+++ b/src/wasi.rs
@@ -825,4 +825,6 @@ extern "C" {
     pub fn arc4random() -> u32;
     pub fn arc4random_buf(a: *mut c_void, b: size_t);
     pub fn arc4random_uniform(a: u32) -> u32;
+
+    pub fn __errno_location() -> *mut ::c_int;
 }