diff --git a/include/opendht/rng.h b/include/opendht/rng.h
index dcc53741..ca3ca9ec 100644
--- a/include/opendht/rng.h
+++ b/include/opendht/rng.h
@@ -17,6 +17,8 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
  */
 
+#pragma once
+
 #include <random>
 
 namespace dht {