diff --git a/src/net.c b/src/net.c
index 8ba0de90..7c4ef43a 100644
--- a/src/net.c
+++ b/src/net.c
@@ -428,7 +428,7 @@ uint64_t DownloadToFileOrBuffer(const char* url, const char* file, BYTE** buffer
 		uprintf("Unable to retrieve file length: %s", WinInetErrorString());
 		goto out;
 	}
-	total_size = strtoull(strsize);
+	total_size = strtoull(strsize, NULL, 10);
 	if (hProgressDialog != NULL) {
 		char msg[128];
 		uprintf("File length: %s", SizeToHumanReadable(total_size, FALSE, FALSE));