diff --git a/src/Sound/fg_fx.cxx b/src/Sound/fg_fx.cxx
index 592bba21b..9f688cd8d 100644
--- a/src/Sound/fg_fx.cxx
+++ b/src/Sound/fg_fx.cxx
@@ -31,6 +31,7 @@
 
 #include "fg_fx.hxx"
 
+#include <algorithm>
 #include <Main/fg_props.hxx>
 #include <Main/globals.hxx>
 #include <Sound/soundmanager.hxx>
diff --git a/src/Systems/electrical.cxx b/src/Systems/electrical.cxx
index c7f746e54..64e5fe838 100644
--- a/src/Systems/electrical.cxx
+++ b/src/Systems/electrical.cxx
@@ -26,6 +26,7 @@
 
 #include <cstdlib>
 #include <cstring>
+#include <algorithm>
 
 #include <simgear/structure/exception.hxx>
 #include <simgear/misc/sg_path.hxx>