diff --git a/src/interfaces/libpgeasy/libpgeasy.c b/src/interfaces/libpgeasy/libpgeasy.c
index 41d3d0429ca8aabd85e4855a45a7de0bf38eacd4..d7fc03e0f3c70fc218cd6a310f475624896a3b81 100644
--- a/src/interfaces/libpgeasy/libpgeasy.c
+++ b/src/interfaces/libpgeasy/libpgeasy.c
@@ -11,7 +11,9 @@
 #include "halt.h"
 #include "libpgeasy.h"
 
+#ifndef NUL
 #define NUL '\0'
+#endif
 
 #ifndef TRUE
 #define TRUE 1