diff --git a/src/end.c b/src/end.c
index b97739a44..37bcef6a3 100644
--- a/src/end.c
+++ b/src/end.c
@@ -3,7 +3,9 @@
 /*-Copyright (c) Robert Patrick Rankin, 2012. */
 /* NetHack may be freely redistributed.  See license for details. */
 
+#ifndef NEED_VARARGS
 #define NEED_VARARGS /* comment line for pre-compiled headers */
+#endif
 
 #include "hack.h"
 #ifndef NO_SIGNAL
diff --git a/src/files.c b/src/files.c
index 205cca5e6..c16fe7915 100644
--- a/src/files.c
+++ b/src/files.c
@@ -3,7 +3,9 @@
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
 
+#ifndef NEED_VARARGS
 #define NEED_VARARGS
+#endif
 
 #include "hack.h"
 #include "dlb.h"