diff --git a/ntcore/src/main/native/cpp/net3/ClientImpl3.h b/ntcore/src/main/native/cpp/net3/ClientImpl3.h
index 7b3e676127..49489c5819 100644
--- a/ntcore/src/main/native/cpp/net3/ClientImpl3.h
+++ b/ntcore/src/main/native/cpp/net3/ClientImpl3.h
@@ -14,6 +14,7 @@
 #include <utility>
 #include <vector>
 
+#include <wpi/StringMap.h>
 #include <wpi/json.h>
 
 #include "PubSubOptions.h"