diff --git a/library/std/src/sys/pal/unix/alloc.rs b/library/std/src/sys/pal/unix/alloc.rs
index 9938c0bac25b0..993bf55edcf10 100644
--- a/library/std/src/sys/pal/unix/alloc.rs
+++ b/library/std/src/sys/pal/unix/alloc.rs
@@ -61,9 +61,7 @@ unsafe impl GlobalAlloc for System {
 cfg_if::cfg_if! {
     if #[cfg(any(
         target_os = "android",
-        target_os = "illumos",
         target_os = "redox",
-        target_os = "solaris",
         target_os = "espidf",
         target_os = "horizon",
         target_os = "vita",