diff --git a/src/manifest.c b/src/manifest.c
index 3c7f4de..be56d4b 100644
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -112,7 +112,7 @@ struct manifest *manifest_from_file(int version, char *component)
 	struct manifest *manifest;
 	char *filename, *conf;
 	int previous = 0;
-	int format_number;
+	unsigned long long int format_number;
 
 	conf = config_output_dir();
 	if (conf == NULL) {
@@ -145,7 +145,7 @@ struct manifest *manifest_from_file(int version, char *component)
 	}
 	c = &line[9];
 	format_number = strtoull(c, NULL, 10);
-	if ((errno < 0) || (format_number <= 0)) {
+	if ((errno < 0) || (format_number == 0)) {
 		//format string shall be a positive integer
 		printf("Unknown file format version in MANIFEST line: %s\n", c);
 		fclose(infile);
diff --git a/src/versions.c b/src/versions.c
index 348a5e6..7ec7e1e 100644
--- a/src/versions.c
+++ b/src/versions.c
@@ -139,7 +139,7 @@ void write_cookiecrumbs_to_download_area(int version)
 	}
 	free(cmd);
 
-	string_or_die(&cmd, "echo %d > %s/%i/format", format, conf, version);
+	string_or_die(&cmd, "echo %llu > %s/%i/format", format, conf, version);
 	if (system(cmd) != 0) {
 		assert(0);
 	}