diff --git a/simgear/misc/zfstream.hxx b/simgear/misc/zfstream.hxx
index b093499f..370eda5e 100644
--- a/simgear/misc/zfstream.hxx
+++ b/simgear/misc/zfstream.hxx
@@ -24,6 +24,10 @@
 #ifndef _zfstream_hxx
 #define _zfstream_hxx
 
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
 #include <simgear/compiler.h>
 
 #ifdef HAVE_ZLIB