diff --git a/Sts1CobcSw/FileSystem/LfsWrapper.cpp b/Sts1CobcSw/FileSystem/LfsWrapper.cpp
index ad0f8004..943f485b 100644
--- a/Sts1CobcSw/FileSystem/LfsWrapper.cpp
+++ b/Sts1CobcSw/FileSystem/LfsWrapper.cpp
@@ -6,7 +6,7 @@
 
 namespace sts1cobcsw::fs
 {
-lfs_t lfs{};
+auto lfs = lfs_t{};
 
 
 // FIXME: For some reason this allocates 1024 bytes on the heap. With LFS_NO_MALLOC defined, it
@@ -141,4 +141,42 @@ auto File::MoveConstructFrom(File * other) noexcept -> void
     other->openFlags_ = 0;
     other->lfsFile_ = {};
 }
+
+
+auto File::WriteInternal(void const * buffer, std::size_t size) -> Result<int>
+{
+    if(not isOpen_)
+    {
+        return ErrorCode::fileNotOpen;
+    }
+    if((openFlags_ & LFS_O_WRONLY) == 0U)
+    {
+        return ErrorCode::unsupportedOperation;
+    }
+    auto nWrittenBytes = lfs_file_write(&lfs, &lfsFile_, buffer, size);
+    if(nWrittenBytes >= 0)
+    {
+        return nWrittenBytes;
+    }
+    return static_cast<ErrorCode>(nWrittenBytes);
+}
+
+
+auto File::ReadInternal(void * buffer, std::size_t size) const -> Result<int>
+{
+    if(not isOpen_)
+    {
+        return ErrorCode::fileNotOpen;
+    }
+    if((openFlags_ & LFS_O_RDONLY) == 0U)
+    {
+        return ErrorCode::unsupportedOperation;
+    }
+    auto nReadBytes = lfs_file_read(&lfs, &lfsFile_, buffer, size);
+    if(nReadBytes >= 0)
+    {
+        return nReadBytes;
+    }
+    return static_cast<ErrorCode>(nReadBytes);
+}
 }
diff --git a/Sts1CobcSw/FileSystem/LfsWrapper.hpp b/Sts1CobcSw/FileSystem/LfsWrapper.hpp
index abcf1f8b..7bb8d975 100644
--- a/Sts1CobcSw/FileSystem/LfsWrapper.hpp
+++ b/Sts1CobcSw/FileSystem/LfsWrapper.hpp
@@ -10,6 +10,7 @@
 #include <etl/string.h>
 
 #include <array>
+#include <cstddef>
 #include <string_view>
 
 
@@ -19,10 +20,6 @@ namespace sts1cobcsw::fs
 using Path = etl::string<LFS_NAME_MAX>;
 
 
-// TODO: Get rid of this global variable or at least hide it in an internal namespace
-extern lfs_t lfs;
-
-
 class File;
 
 [[nodiscard]] auto Mount() -> Result<void>;
@@ -43,9 +40,6 @@ class File
 
     friend auto Open(std::string_view path, unsigned int flags) -> Result<File>;
 
-    // TODO: Read() and Write() should be implemented like ReadFrom() and WriteTo() in Fram.hpp,
-    // including forwarding to functions in an internal namespace. This way we can move lfs back
-    // into the .cpp file.
     template<typename T>
     [[nodiscard]] auto Read(T * t) const -> Result<int>;
     template<typename T>
@@ -58,6 +52,8 @@ class File
     // Only allow creation of File class through friend function Open()
     File() = default;
     auto MoveConstructFrom(File * other) noexcept -> void;
+    [[nodiscard]] auto WriteInternal(void const * buffer, std::size_t size) -> Result<int>;
+    [[nodiscard]] auto ReadInternal(void * buffer, std::size_t size) const -> Result<int>;
 
     Path path_ = "";
     unsigned int openFlags_ = 0;
diff --git a/Sts1CobcSw/FileSystem/LfsWrapper.ipp b/Sts1CobcSw/FileSystem/LfsWrapper.ipp
index 1e9187b7..53932d70 100644
--- a/Sts1CobcSw/FileSystem/LfsWrapper.ipp
+++ b/Sts1CobcSw/FileSystem/LfsWrapper.ipp
@@ -2,8 +2,6 @@
 
 #include <Sts1CobcSw/FileSystem/LfsWrapper.hpp>
 
-#include <littlefs/lfs.h>
-
 #include "Sts1CobcSw/FileSystem/ErrorsAndResult.hpp"
 
 
@@ -12,39 +10,13 @@ namespace sts1cobcsw::fs
 template<typename T>
 auto File::Read(T * t) const -> Result<int>
 {
-    if(not isOpen_)
-    {
-        return ErrorCode::fileNotOpen;
-    }
-    if(not(openFlags_ & LFS_O_RDONLY))
-    {
-        return ErrorCode::unsupportedOperation;
-    }
-    auto nReadBytes = lfs_file_read(&lfs, &lfsFile_, t, sizeof(T));
-    if(nReadBytes >= 0)
-    {
-        return nReadBytes;
-    }
-    return static_cast<ErrorCode>(nReadBytes);
+    return ReadInternal(t, sizeof(T));
 }
 
 
 template<typename T>
 auto File::Write(T const & t) -> Result<int>
 {
-    if(not isOpen_)
-    {
-        return ErrorCode::fileNotOpen;
-    }
-    if(not(openFlags_ & LFS_O_WRONLY))
-    {
-        return ErrorCode::unsupportedOperation;
-    }
-    auto nWrittenBytes = lfs_file_write(&lfs, &lfsFile_, &t, sizeof(T));
-    if(nWrittenBytes >= 0)
-    {
-        return nWrittenBytes;
-    }
-    return static_cast<ErrorCode>(nWrittenBytes);
+    return WriteInternal(&t, sizeof(T));
 }
 }