diff --git a/third_party/dosfstools/dosfstools.bzl b/third_party/dosfstools/dosfstools.bzl
index 6202cfe..61b1ca2 100644
--- a/third_party/dosfstools/dosfstools.bzl
+++ b/third_party/dosfstools/dosfstools.bzl
@@ -26,7 +26,7 @@
         "src/msdos_fs.h",
         ":version.h",
     ],
-    copts = ["-DHAVE_ENDIAN_H"],
+    copts = ["-DHAVE_ENDIAN_H", "-DHAVE_VASPRINTF"],
     visibility = ["//visibility:public"],
     includes = ["."],
 )