diff --git a/compiler/rustc_session/src/config/cfg.rs b/compiler/rustc_session/src/config/cfg.rs
index 84a26af6b54..12ac666574f 100644
--- a/compiler/rustc_session/src/config/cfg.rs
+++ b/compiler/rustc_session/src/config/cfg.rs
@@ -315,6 +315,11 @@ macro_rules! ins_sym {
         ins_none!(sym::target_thread_local);
     }
 
+    if sess.target.vendor_symbol().as_str() == "alpine" {
+        ins_none!(sym::libc_unstable_musl_v1_2); // 0.2.190+
+        ins_none!(sym::libc_unstable_musl_v1_2_3); // 0.2.187-0.2.189
+    }
+
     ins_sym!(sym::target_vendor, sess.target.vendor_symbol());
 
     // If the user wants a test runner, then add the test cfg.
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index e533458ab53..ee4276ad332 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1194,6 +1194,8 @@
         lhs,
         lib,
         libc,
+        libc_unstable_musl_v1_2,
+        libc_unstable_musl_v1_2_3,
         lifetime,
         lifetime_capture_rules_2024,
         lifetimes,