diff --git a/stm/mpconfigport.h b/stm/mpconfigport.h
index 1d79243f9b..51e4bb9a82 100644
--- a/stm/mpconfigport.h
+++ b/stm/mpconfigport.h
@@ -13,6 +13,9 @@
 
 #define BYTES_PER_WORD (4)
 
+#define UINT_FMT "%lu"
+#define INT_FMT "%ld"
+
 typedef int32_t machine_int_t; // must be pointer size
 typedef uint32_t machine_uint_t; // must be pointer size
 typedef void *machine_ptr_t; // must be of pointer size