diff --git a/alib/src/std/istream.h b/alib/src/std/istream.h
index 4b285b3d2b97247be91fd6a0ffdfc5c53a4cde37..3d5167191f0463ca0ca6b4760e7915b0b166f1f1 100644
--- a/alib/src/std/istream.h
+++ b/alib/src/std/istream.h
@@ -1,4 +1,9 @@
+#ifndef ISTREAM_H_
+#define ISTREAM_H_
+
 #include <iostream>
 #include <string>
 
 std::istream& operator>>(std::istream& in, const std::string& str);
+
+#endif
\ No newline at end of file