diff --git a/src/HttpParser.h b/src/HttpParser.h
index e298fe5..8afe5e6 100644
--- a/src/HttpParser.h
+++ b/src/HttpParser.h
@@ -27,6 +27,7 @@
 #include <algorithm>
 #include <climits>
 #include <string_view>
+#include <map>
 #include "MoveOnlyFunction.h"
 #include "ChunkedEncoding.h"