diff --git a/include/mgba-util/common.h b/include/mgba-util/common.h
index f8b705e11..1934ed87b 100644
--- a/include/mgba-util/common.h
+++ b/include/mgba-util/common.h
@@ -121,7 +121,7 @@ typedef intptr_t ssize_t;
 // newlib doesn't support %z properly by default
 #define PRIz ""
 #elif defined(_WIN64)
-#define PRIz "ll"
+#define PRIz "I64"
 #elif defined(_WIN32)
 #define PRIz ""
 #else