diff --git a/src/security/validator-regex.cpp b/src/security/validator-regex.cpp
index d84f897..c0797c7 100644
--- a/src/security/validator-regex.cpp
+++ b/src/security/validator-regex.cpp
@@ -36,7 +36,7 @@
   , m_certificateCache(certificateCache)
 {
   if (!static_cast<bool>(m_certificateCache))
-    m_certificateCache = make_shared<CertificateCacheTtl>(m_face.ioService());
+    m_certificateCache = make_shared<CertificateCacheTtl>(boost::ref(m_face.getIoService()));
 }
 
 void