diff --git a/src/platform.h b/src/platform.h
index 6ccbb8d6d..a56328485 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#define _LP64 0 /* fix a warning in pdcurses 3.4 */
+
 #ifndef UNILIB_H
 #define UNILIB_H