diff --git a/server/core/load_utils.cc b/server/core/load_utils.cc
index d21522e0c..1f34b49e1 100644
--- a/server/core/load_utils.cc
+++ b/server/core/load_utils.cc
@@ -24,6 +24,7 @@
 #include <string.h>
 #include <dlfcn.h>
 #include <algorithm>
+#include <string>
 
 #include <maxscale/modinfo.h>
 #include <maxscale/log_manager.h>
diff --git a/server/modules/monitor/mariadbmon/mysql_mon.cc b/server/modules/monitor/mariadbmon/mysql_mon.cc
index 51586f3db..0c83bf942 100644
--- a/server/modules/monitor/mariadbmon/mysql_mon.cc
+++ b/server/modules/monitor/mariadbmon/mysql_mon.cc
@@ -2372,7 +2372,7 @@ monitorMain(void *arg)
             }
         }
 
-        ss_dassert(handle->master == root_master);
+        ss_dassert(root_master == NULL || handle->master == root_master);
         ss_dassert(!root_master ||
                    ((root_master->server->status & (SERVER_SLAVE | SERVER_MASTER))
                     != (SERVER_SLAVE | SERVER_MASTER)));