diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index 7782958f91461bb1ccc4c6417dfd5d892dbee521..02b89549a362a2b147b9d1d8503f690c86ff66ef 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -843,12 +843,16 @@ impl X509Extension {
         }
     }
 
-    #[corresponds(X509V3_EXT_add_alias)]
-    pub fn add_alias(to: Nid, from: Nid) -> Result<(), ErrorStack> {
-        unsafe {
-            ffi::init();
-            cvt(ffi::X509V3_EXT_add_alias(to.as_raw(), from.as_raw())).map(|_| ())
-        }
+    /// Adds an alias for an extension
+    ///
+    /// This corresponds to [`X509V3_EXT_add_alias`]
+    ///
+    /// # Safety
+    ///
+    /// This method modifies global state without locking and therefore is not thread safe
+    pub unsafe fn add_alias(to: Nid, from: Nid) -> Result<(), ErrorStack> {
+        ffi::init();
+        cvt(ffi::X509V3_EXT_add_alias(to.as_raw(), from.as_raw())).map(|_| ())
     }
 }