diff --git a/openssl/src/ssl/mod.rs b/openssl/src/ssl/mod.rs
index 8cc1c6007482b1596da2d97c4383adcec20e3c6c..954bb5e780ca6d1a312f0247c98598f53e2b5ec4 100644
--- a/openssl/src/ssl/mod.rs
+++ b/openssl/src/ssl/mod.rs
@@ -415,6 +415,9 @@ pub enum SniError {
 /// A builder for `SslContext`s.
 pub struct SslContextBuilder(*mut ffi::SSL_CTX);
 
+unsafe impl Sync for SslContextBuilder {}
+unsafe impl Send for SslContextBuilder {}
+
 impl Drop for SslContextBuilder {
     fn drop(&mut self) {
         unsafe { ffi::SSL_CTX_free(self.as_ptr()) }