diff --git a/makerom/lib.h b/makerom/lib.h
index 1799a9f..e0ef089 100644
--- a/makerom/lib.h
+++ b/makerom/lib.h
@@ -13,6 +13,7 @@
 #include <math.h>
 #include <dirent.h>
 #include <wchar.h>
+#include <inttypes.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
diff --git a/makerom/utils.c b/makerom/utils.c
index 45b509d..1321168 100644
--- a/makerom/utils.c
+++ b/makerom/utils.c
@@ -305,7 +305,7 @@ u8* ImportFile(char *file, u64 size)
 	u64 fsize = GetFileSize_u64(file);
 	if(size > 0){
 		if(size != fsize){
-			fprintf(stderr,"[!] %s has an invalid size (0x%llx)\n",file, fsize);
+			fprintf(stderr,"[!] %s has an invalid size (0x%"PRIx64")\n",file, fsize);
 			return NULL;
 		}
 	}