diff --git a/src/io/deflate_ostream.hpp b/src/io/deflate_ostream.hpp
index 39678843..a029e021 100644
--- a/src/io/deflate_ostream.hpp
+++ b/src/io/deflate_ostream.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <iostream>
 #include <streambuf>
 #include <memory>
diff --git a/src/io/devices/StdfsDevice.hpp b/src/io/devices/StdfsDevice.hpp
index 69b12234..677cad25 100644
--- a/src/io/devices/StdfsDevice.hpp
+++ b/src/io/devices/StdfsDevice.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "Device.hpp"
 
 namespace io {
diff --git a/src/io/memory_ostream.hpp b/src/io/memory_ostream.hpp
index d8849704..3ff14a99 100644
--- a/src/io/memory_ostream.hpp
+++ b/src/io/memory_ostream.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <iostream>
 #include <streambuf>
 #include <cstring>