diff --git a/lib/data/fluxmap.h b/lib/data/fluxmap.h
index 8f9b0bbc..3b1ee633 100644
--- a/lib/data/fluxmap.h
+++ b/lib/data/fluxmap.h
@@ -4,6 +4,7 @@
 #include "lib/core/bytes.h"
 #include "protocol.h"
 #include "fmt/format.h"
+#include <mutex>
 
 class RawBits;