diff --git a/pila.c b/pila.c
index 2e15262..26b3881 100644
--- a/pila.c
+++ b/pila.c
@@ -10,6 +10,8 @@
 
 #define BOX_INTN(n) (Value){.kind = VAL_INT, .intn = n}
 #define BOX_STR(n) (Value){.kind = VAL_STR, .str = n}
+#define PILA_TRUE ((u64)1)
+#define PILA_FALSE ((u64)0)
 
 typedef struct UserWord UserWord;
 typedef struct Word Word;