diff --git a/simgear/props/props_io.cxx b/simgear/props/props_io.cxx
index df68d585..3938745f 100644
--- a/simgear/props/props_io.cxx
+++ b/simgear/props/props_io.cxx
@@ -27,6 +27,7 @@
 #include <iostream>
 #include <fstream>
 #include <string>
+#include <cstring>		// strcmp()
 #include <vector>
 #include <map>