diff --git a/src/archiver.c b/src/archiver.c
index fbb91a8..89b2927 100644
--- a/src/archiver.c
+++ b/src/archiver.c
@@ -1301,6 +1301,8 @@ char *simple_archiver_error_to_string(enum SDArchiverStateReturns error) {
       return "Failed to extract symlink (internal error)";
     case SDAS_FAILED_TO_CHANGE_CWD:
       return "Failed to change current working directory";
+    case SDAS_INVALID_WRITE_VERSION:
+      return "Unsupported write version file format";
     default:
       return "Unknown error";
   }
@@ -1332,6 +1334,20 @@ void simple_archiver_free_state(SDArchiverState **state) {
 
 int simple_archiver_write_all(FILE *out_f, SDArchiverState *state,
                               const SDArchiverLinkedList *filenames) {
+  switch (state->parsed->write_version) {
+    case 0:
+      return simple_archiver_write_v0(out_f, state, filenames);
+    case 1:
+      return simple_archiver_write_v1(out_f, state, filenames);
+    default:
+      fprintf(stderr, "ERROR: Unsupported write version %u!\n",
+              state->parsed->write_version);
+      return SDAS_INVALID_WRITE_VERSION;
+  }
+}
+
+int simple_archiver_write_v0(FILE *out_f, SDArchiverState *state,
+                             const SDArchiverLinkedList *filenames) {
   // First create a "set" of absolute paths to given filenames.
   __attribute__((cleanup(simple_archiver_hash_map_free)))
   SDArchiverHashMap *abs_filenames = simple_archiver_hash_map_init();
@@ -1471,6 +1487,13 @@ int simple_archiver_write_all(FILE *out_f, SDArchiverState *state,
   return SDAS_SUCCESS;
 }
 
+int simple_archiver_write_v1(FILE *out_f, SDArchiverState *state,
+                             const SDArchiverLinkedList *filenames) {
+  // TODO Impl.
+  fprintf(stderr, "Writing v1 unimplemented\n");
+  return SDAS_INTERNAL_ERROR;
+}
+
 int simple_archiver_parse_archive_info(FILE *in_f, int_fast8_t do_extract,
                                        const SDArchiverState *state) {
   uint8_t buf[32];
diff --git a/src/archiver.h b/src/archiver.h
index 51b6abc..2b8fbf2 100644
--- a/src/archiver.h
+++ b/src/archiver.h
@@ -51,7 +51,8 @@ enum SDArchiverStateReturns {
   SDAS_INTERNAL_ERROR,
   SDAS_FAILED_TO_CREATE_MAP,
   SDAS_FAILED_TO_EXTRACT_SYMLINK,
-  SDAS_FAILED_TO_CHANGE_CWD
+  SDAS_FAILED_TO_CHANGE_CWD,
+  SDAS_INVALID_WRITE_VERSION
 };
 
 /// Returned pointer must not be freed.
@@ -65,6 +66,12 @@ void simple_archiver_free_state(SDArchiverState **state);
 int simple_archiver_write_all(FILE *out_f, SDArchiverState *state,
                               const SDArchiverLinkedList *filenames);
 
+int simple_archiver_write_v0(FILE *out_f, SDArchiverState *state,
+                             const SDArchiverLinkedList *filenames);
+
+int simple_archiver_write_v1(FILE *out_f, SDArchiverState *state,
+                             const SDArchiverLinkedList *filenames);
+
 /// Returns zero on success.
 int simple_archiver_parse_archive_info(FILE *in_f, int_fast8_t do_extract,
                                        const SDArchiverState *state);
diff --git a/src/parser.c b/src/parser.c
index 5da4653..2bc5b25 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -169,6 +169,9 @@ void simple_archiver_print_usage(void) {
   fprintf(stderr,
           "--temp-files-dir <dir> : where to store temporary files created "
           "when compressing (defaults to current working directory)\n");
+  fprintf(stderr,
+          "--write-version <version> : Force write version file format "
+          "(default 1)\n");
   fprintf(stderr,
           "-- : specifies remaining arguments are files to archive/extract\n");
   fprintf(
@@ -189,6 +192,7 @@ SDArchiverParsed simple_archiver_create_parsed(void) {
   parsed.working_files = NULL;
   parsed.temp_dir = NULL;
   parsed.user_cwd = NULL;
+  parsed.write_version = 0;
 
   return parsed;
 }
@@ -299,6 +303,26 @@ int simple_archiver_parse_args(int argc, const char **argv,
         out->temp_dir = argv[1];
         --argc;
         ++argv;
+      } else if (strcmp(argv[0], "--write-version") == 0) {
+        if (argc < 2) {
+          fprintf(stderr,
+                  "ERROR: --write-version expects an integer argument!\n");
+          simple_archiver_print_usage();
+          return 1;
+        }
+        int version = atoi(argv[1]);
+        if (version < 0) {
+          fprintf(stderr, "ERROR: --write-version cannot be negative!\n");
+          simple_archiver_print_usage();
+          return 1;
+        } else if (version > 1) {
+          fprintf(stderr, "ERROR: --write-version must be 0 or 1!\n");
+          simple_archiver_print_usage();
+          return 1;
+        }
+        out->write_version = (uint32_t)version;
+        --argc;
+        ++argv;
       } else if (argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == 0) {
         is_remaining_args = 1;
       } else if (argv[0][0] != '-') {
diff --git a/src/parser.h b/src/parser.h
index ad2e472..1c74427 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -51,6 +51,8 @@ typedef struct SDArchiverParsed {
   const char *temp_dir;
   /// Dir specified by "-C".
   const char *user_cwd;
+  /// Currently only 0 and 1 is supported.
+  uint32_t write_version;
 } SDArchiverParsed;
 
 typedef struct SDArchiverFileInfo {