diff --git a/firmware/application/file.cpp b/firmware/application/file.cpp
index ae846892..ef7dc3ed 100644
--- a/firmware/application/file.cpp
+++ b/firmware/application/file.cpp
@@ -25,13 +25,6 @@
 #include <locale>
 #include <codecvt>
 
-/* Values added to FatFs FRESULT enum, values outside the FRESULT data type */
-static_assert(sizeof(FIL::err) == 1, "FatFs FIL::err size not expected.");
-#define FR_DISK_FULL	(0x100)
-#define FR_EOF          (0x101)
-#define FR_BAD_SEEK		(0x102)
-#define FR_UNEXPECTED	(0x103)
-
 Optional<File::Error> File::open_fatfs(const std::filesystem::path& filename, BYTE mode) {
 	auto result = f_open(&f, reinterpret_cast<const TCHAR*>(filename.c_str()), mode);
 	if( result == FR_OK ) {
diff --git a/firmware/application/file.hpp b/firmware/application/file.hpp
index 4c59f7f0..42cce7f5 100644
--- a/firmware/application/file.hpp
+++ b/firmware/application/file.hpp
@@ -233,6 +233,16 @@ space_info space(const path& p);
 
 std::filesystem::path next_filename_stem_matching_pattern(std::filesystem::path filename_stem_pattern);
 
+/* Values added to FatFs FRESULT enum, values outside the FRESULT data type */
+static_assert(sizeof(FIL::err) == 1, "FatFs FIL::err size not expected.");
+
+/* Dangerous to expose these, as FatFs native error values are byte-sized. However,
+ * my filesystem_error implemetation is fine with it. */
+#define FR_DISK_FULL	(0x100)
+#define FR_EOF          (0x101)
+#define FR_BAD_SEEK		(0x102)
+#define FR_UNEXPECTED	(0x103)
+
 class File {
 public:
 	using Size = uint64_t;