diff --git a/src/ssl/test/settings_writer.cc b/src/ssl/test/settings_writer.cc
index 8605222fe..78598a869 100644
--- a/src/ssl/test/settings_writer.cc
+++ b/src/ssl/test/settings_writer.cc
@@ -75,8 +75,11 @@ bool SettingsWriter::Commit() {
   }
   bssl::UniquePtr<uint8_t> free_settings(settings);
 
-  using ScopedFILE = std::unique_ptr<FILE, decltype(&fclose)>;
-  ScopedFILE file(fopen(path_.c_str(), "w"), fclose);
+  struct FileCloser {
+    void operator()(FILE *f) const { fclose(f); }
+  };
+  using ScopedFILE = std::unique_ptr<FILE, FileCloser>;
+  ScopedFILE file(fopen(path_.c_str(), "w"));
   if (!file) {
     return false;
   }