diff --git a/src/lib.rs b/src/lib.rs
index 4e08482..44c56c3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -328,7 +328,8 @@
     }
 
     /// This method is only available when the `"nightly"` feature is enabled.
-    #[cfg(super_unstable)]
+    #[doc(hidden)]
+    #[cfg(any(feature = "nightly", super_unstable))]
     pub fn unstable(self) -> proc_macro::Span {
         self.inner.unstable()
     }