diff --git a/btparser/lexer.h b/btparser/lexer.h
index c79094e..72fc439 100644
--- a/btparser/lexer.h
+++ b/btparser/lexer.h
@@ -5,6 +5,7 @@
 #include <unordered_map>
 #include <functional>
 #include <string>
+#include <stdexcept>
 
 class Lexer
 {