diff --git a/src/nghttp.h b/src/nghttp.h
index c4f7c723..1162c80c 100644
--- a/src/nghttp.h
+++ b/src/nghttp.h
@@ -35,6 +35,7 @@
 #include <vector>
 #include <set>
 #include <chrono>
+#include <memory>
 
 #include <openssl/ssl.h>