diff --git a/src/amulet/nbt/export.hpp b/src/amulet/nbt/export.hpp
index 7151e019..06018210 100644
--- a/src/amulet/nbt/export.hpp
+++ b/src/amulet/nbt/export.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #ifndef AMULET_NBT_EXPORT
     #ifdef _WIN32
         #ifdef ExportAmuletNBT
diff --git a/src/amulet/nbt/tag/list_methods.hpp b/src/amulet/nbt/tag/list_methods.hpp
index 9712a741..2276d62a 100644
--- a/src/amulet/nbt/tag/list_methods.hpp
+++ b/src/amulet/nbt/tag/list_methods.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <amulet/nbt/tag/compound.hpp>
 #include <amulet/nbt/tag/list.hpp>
 
diff --git a/src/amulet/nbt/tag/serialisation.py.hpp b/src/amulet/nbt/tag/serialisation.py.hpp
index cb111801..840b1f79 100644
--- a/src/amulet/nbt/tag/serialisation.py.hpp
+++ b/src/amulet/nbt/tag/serialisation.py.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #define SerialiseTag(CLSNAME)                                                                                                     \
     auto to_nbt_##CLSNAME = [](                                                                                                   \
                                 const Amulet::NBT::CLSNAME& self,                                                                 \