diff --git a/H/Yap.h b/H/Yap.h
index dedf68d3f..5598ef636 100644
--- a/H/Yap.h
+++ b/H/Yap.h
@@ -158,10 +158,16 @@
 /*   */ typedef int Int;
 /*   */ typedef unsigned int UInt;
 
+#define Int_FORMAT "%d"
+#define UInt_FORMAT "%u"
+
 #elif SIZEOF_LONG_INT==4
 /*   */ typedef long int Int;
 /*   */ typedef unsigned long int UInt;
 
+#define Int_FORMAT "%l"
+#define UInt_FORMAT "%ul"
+
 #else
 #	error Yap require integer types of the same size as a pointer
 #endif
@@ -180,14 +186,23 @@
 /*   */ typedef int Int;
 /*   */ typedef unsigned int UInt;
 
+#define Int_FORMAT "%d"
+#define UInt_FORMAT "%ud"
+
 #elif SIZEOF_LONG_INT==8
 /*   */ typedef long int Int;
 /*   */ typedef unsigned long int UInt;
 
+#define Int_FORMAT "%l"
+#define UInt_FORMAT "%ul"
+
 #   elif SIZEOF_LONG_LONG_INT==8
 /*   */ typedef long long int Int;
 /*   */ typedef unsigned long long int UInt;
 
+#define Int_FORMAT "%I64d"
+#define UInt_FORMAT "%I64u"
+
 #   else
 #	error Yap requires integer types of the same size as a pointer
 #   endif