diff --git a/miniz_zip.c b/miniz_zip.c
index 8e16cf7..b529759 100644
--- a/miniz_zip.c
+++ b/miniz_zip.c
@@ -3478,15 +3478,15 @@ mz_bool mz_zip_writer_add_read_buf_callback(mz_zip_archive *pZip, const char *pA
     mz_zip_internal_state *pState;
     mz_uint64 file_ofs = 0, cur_archive_header_file_ofs;
 
-    if (!(level_and_flags & MZ_ZIP_FLAG_ASCII_FILENAME))
-        gen_flags |= MZ_ZIP_GENERAL_PURPOSE_BIT_FLAG_UTF8;
-
     if ((int)level_and_flags < 0)
         level_and_flags = MZ_DEFAULT_LEVEL;
     level = level_and_flags & 0xF;
 
     gen_flags = (level_and_flags & MZ_ZIP_FLAG_WRITE_HEADER_SET_SIZE) ? 0 : MZ_ZIP_LDH_BIT_FLAG_HAS_LOCATOR;
 
+    if (!(level_and_flags & MZ_ZIP_FLAG_ASCII_FILENAME))
+        gen_flags |= MZ_ZIP_GENERAL_PURPOSE_BIT_FLAG_UTF8;
+
     /* Sanity checks */
     if ((!pZip) || (!pZip->m_pState) || (pZip->m_zip_mode != MZ_ZIP_MODE_WRITING) || (!pArchive_name) || ((comment_size) && (!pComment)) || (level > MZ_UBER_COMPRESSION))
         return mz_zip_set_error(pZip, MZ_ZIP_INVALID_PARAMETER);