diff --git a/riscv/log_file.h b/riscv/log_file.h
index d039859d..9e210bba 100644
--- a/riscv/log_file.h
+++ b/riscv/log_file.h
@@ -31,7 +31,7 @@ public:
   FILE *get() { return wrapped_file ? wrapped_file.get() : stderr; }
 
 private:
-  std::unique_ptr<FILE, decltype(&fclose)> wrapped_file;
+  std::unique_ptr<FILE, int(*)(FILE*)> wrapped_file;
 };
 
 #endif