diff --git a/openssl/src/x509/extension.rs b/openssl/src/x509/extension.rs
index 4f8a3c3b..66b218ad 100644
--- a/openssl/src/x509/extension.rs
+++ b/openssl/src/x509/extension.rs
@@ -77,7 +77,7 @@ impl fmt::Display for KeyUsageOption {
     }
 }
 
-#[derive(Clone,Copy)]
+#[derive(Clone)]
 pub enum ExtKeyUsageOption {
     ServerAuth,
     ClientAuth,
@@ -90,6 +90,8 @@ pub enum ExtKeyUsageOption {
     MsSgc,
     MsEfs,
     NsSgc,
+    /// An arbitrary key usage by OID.
+    Other(String),
 }
 
 impl fmt::Display for ExtKeyUsageOption {
@@ -106,6 +108,7 @@ impl fmt::Display for ExtKeyUsageOption {
             &ExtKeyUsageOption::MsSgc => "msSGC",
             &ExtKeyUsageOption::MsEfs => "msEFS",
             &ExtKeyUsageOption::NsSgc =>"nsSGC",
+            &ExtKeyUsageOption::Other(ref s) => &s[..],
         })
     }
 }
diff --git a/openssl/src/x509/tests.rs b/openssl/src/x509/tests.rs
index ca9ce68c..66dc33d3 100644
--- a/openssl/src/x509/tests.rs
+++ b/openssl/src/x509/tests.rs
@@ -6,7 +6,7 @@ use std::fs::File;
 use crypto::hash::Type::{SHA256};
 use x509::{X509, X509Generator};
 use x509::KeyUsage::{DigitalSignature, KeyEncipherment};
-use x509::ExtKeyUsage::{ClientAuth, ServerAuth};
+use x509::ExtKeyUsage::{self, ClientAuth, ServerAuth};
 use nid::Nid;
 
 #[test]
@@ -17,7 +17,7 @@ fn test_cert_gen() {
         .set_CN("test_me")
         .set_sign_hash(SHA256)
         .set_usage(&[DigitalSignature, KeyEncipherment])
-        .set_ext_usage(&[ClientAuth, ServerAuth]);
+        .set_ext_usage(&[ClientAuth, ServerAuth, ExtKeyUsage::Other("2.999".to_owned())]);
 
     let (cert, pkey) = gen.generate().unwrap();
     cert.write_pem(&mut io::sink()).unwrap();