diff --git a/project/Core/Inc/tftp.h b/project/Core/Inc/tftp.h
index e33e855..5a99147 100644
--- a/project/Core/Inc/tftp.h
+++ b/project/Core/Inc/tftp.h
@@ -30,6 +30,7 @@ void tftp_server_init(void);
 void tftp_server_deinit(void);
 void tftp_custom_fseek(tftp_custom_file_t* handle, size_t offset, int whence);
 size_t tftp_custom_fread(void* buf, size_t bytes, tftp_custom_file_t* handle);
+size_t tftp_custom_fwrite(void* buf, size_t bytes, tftp_custom_file_t* handle);
 
 #ifdef __cplusplus
 }
diff --git a/project/Core/Src/tftp.c b/project/Core/Src/tftp.c
index 6a4b937..1a46967 100644
--- a/project/Core/Src/tftp.c
+++ b/project/Core/Src/tftp.c
@@ -82,6 +82,27 @@ size_t tftp_custom_fread(void* buf, size_t bytes, tftp_custom_file_t* handle) {
     return bytes;
 }
 
+/**
+ * @brief tftp custom file functions to write the data
+ *        auto rolling over the offset
+ *
+ * @param buf The buffer to write the data to
+ * @param bytes The number of bytes to write
+ * @param handle The handle to the file to write to
+ * @return The number of bytes written
+ */
+size_t tftp_custom_fwrite(void* buf, size_t bytes, tftp_custom_file_t* handle) {
+    if (handle->ofset + bytes > handle->len) {
+        bytes = handle->len - handle->ofset;
+    }
+    memcpy(handle->data + handle->ofset, buf, bytes);
+    handle->ofset += bytes;
+    if (handle->ofset > handle->len) {
+        bytes = 0;
+    }
+    return bytes;
+}
+
 /**
  * @brief tftp helper functions
  */