diff --git a/src/header/stdlib/mod.rs b/src/header/stdlib/mod.rs
--- a/src/header/stdlib/mod.rs
+++ b/src/header/stdlib/mod.rs
@@ -1233,7 +1233,11 @@
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/getenv.html>.
 // #[unsafe(no_mangle)]
 pub unsafe extern "C" fn secure_getenv(name: *const c_char) -> *mut c_char {
-    unimplemented!();
+    // Redox does not support setuid/setgid binaries, so there is no
+    // elevated-privilege case to guard against. Always delegate to getenv.
+    // If setuid support is ever added, this must check real vs effective
+    // uid/gid and return NULL when they differ.
+    unsafe { getenv(name) }
 }
 
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/drand48.html>.