diff --git a/src/AIModel/AIFlightPlanCreate.cxx b/src/AIModel/AIFlightPlanCreate.cxx
index 7a8fd7b45..1fe7dbd3f 100644
--- a/src/AIModel/AIFlightPlanCreate.cxx
+++ b/src/AIModel/AIFlightPlanCreate.cxx
@@ -22,6 +22,8 @@
 #  include <config.h>
 #endif
 
+#include <algorithm>
+
 #include <cstdlib>
 #include <cstdio>
 
diff --git a/src/Navaids/routePath.cxx b/src/Navaids/routePath.cxx
index 1a00d8381..87779c429 100644
--- a/src/Navaids/routePath.cxx
+++ b/src/Navaids/routePath.cxx
@@ -3,6 +3,8 @@
 #  include "config.h"
 #endif
 
+#include <algorithm>
+
 #include <Navaids/routePath.hxx>
 
 #include <simgear/structure/exception.hxx>