diff --git a/tests/allocator.hpp b/tests/allocator.hpp
index a2022fe..677fbe4 100644
--- a/tests/allocator.hpp
+++ b/tests/allocator.hpp
@@ -1,7 +1,10 @@
-#pragma once
+#ifndef HEADER_TEST_ALLOCATOR_HPP
+#define HEADER_TEST_ALLOCATOR_HPP
 
 #include <stddef.h>
 
 void* memory_allocate(size_t size);
 size_t memory_size(void* ptr);
 void memory_deallocate(void* ptr);
+
+#endif
diff --git a/tests/common.hpp b/tests/common.hpp
index 306fb18..b466c09 100644
--- a/tests/common.hpp
+++ b/tests/common.hpp
@@ -1,3 +1,8 @@
+#ifndef HEADER_TEST_COMMON_HPP
+#define HEADER_TEST_COMMON_HPP
+
 #include "test.hpp"
 
 using namespace pugi;
+
+#endif
diff --git a/tests/helpers.hpp b/tests/helpers.hpp
index 6648806..b160a85 100644
--- a/tests/helpers.hpp
+++ b/tests/helpers.hpp
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef HEADER_TEST_HELPERS_HPP
+#define HEADER_TEST_HELPERS_HPP
 
 #include "common.hpp"
 
@@ -93,3 +94,4 @@ template <typename T> static void generic_rel_ops_test(T obj1, T obj2)
 	CHECK(!(obj1 >= obj2));
 }
 
+#endif
diff --git a/tests/test.hpp b/tests/test.hpp
index 49fd3a1..5559baa 100644
--- a/tests/test.hpp
+++ b/tests/test.hpp
@@ -1,5 +1,5 @@
-#ifndef HEADER_TEST_HPP
-#define HEADER_TEST_HPP
+#ifndef HEADER_TEST_TEST_HPP
+#define HEADER_TEST_TEST_HPP
 
 #include "../src/pugixml.hpp"
 
diff --git a/tests/writer_string.hpp b/tests/writer_string.hpp
index 1004fa0..a862922 100644
--- a/tests/writer_string.hpp
+++ b/tests/writer_string.hpp
@@ -1,5 +1,5 @@
-#ifndef HEADER_WRITER_STRING_HPP
-#define HEADER_WRITER_STRING_HPP
+#ifndef HEADER_TEST_WRITER_STRING_HPP
+#define HEADER_TEST_WRITER_STRING_HPP
 
 #include "../src/pugixml.hpp"