diff --git a/opentelemetry-api/src/lib.rs b/opentelemetry-api/src/lib.rs
index 2a07884bc8..e19182726f 100644
--- a/opentelemetry-api/src/lib.rs
+++ b/opentelemetry-api/src/lib.rs
@@ -73,13 +73,16 @@ pub mod time {
     use std::time::SystemTime;
 
     #[doc(hidden)]
-    #[cfg(not(target_arch = "wasm32"))]
+    #[cfg(any(
+        not(target_arch = "wasm32"),
+        all(target_arch = "wasm32", target_os = "wasi")
+    ))]
     pub fn now() -> SystemTime {
         SystemTime::now()
     }
 
     #[doc(hidden)]
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))]
     pub fn now() -> SystemTime {
         SystemTime::UNIX_EPOCH + std::time::Duration::from_millis(js_sys::Date::now() as u64)
     }