diff --git a/src/Lexer.h b/src/Lexer.h
index 0a05c904..0e08cf52 100644
--- a/src/Lexer.h
+++ b/src/Lexer.h
@@ -30,6 +30,7 @@
 #include <string>
 #include <map>
 #include <vector>
+#include <tuple>
 #include <cstddef>
 
 class Lexer