diff --git a/kindlecomicconverter/comic2ebook.py b/kindlecomicconverter/comic2ebook.py
index b844568..780b967 100755
--- a/kindlecomicconverter/comic2ebook.py
+++ b/kindlecomicconverter/comic2ebook.py
@@ -43,7 +43,7 @@ from psutil import virtual_memory, disk_usage
 from html import escape as hescape
 import pymupdf
 
-from .shared import getImageFileName, walkSort, walkLevel, sanitizeTrace, subprocess_run, dot_clean
+from .shared import IMAGE_TYPES, getImageFileName, walkSort, walkLevel, sanitizeTrace, subprocess_run, dot_clean
 from .comicarchive import SEVENZIP, available_archive_tools
 from . import comic2panel
 from . import image
@@ -1036,7 +1036,7 @@ def removeNonImages(filetree):
     for root, dirs, files in os.walk(filetree):
         for name in files:
             _, ext = getImageFileName(name)
-            if ext not in ('.png', '.jpg', '.jpeg', '.gif', '.webp', '.jp2', '.avif'):
+            if ext not in IMAGE_TYPES:
                 if os.path.exists(os.path.join(root, name)):
                     os.remove(os.path.join(root, name))
     # remove empty nested folders
diff --git a/kindlecomicconverter/comicarchive.py b/kindlecomicconverter/comicarchive.py
index ba488a8..f3b6caa 100644
--- a/kindlecomicconverter/comicarchive.py
+++ b/kindlecomicconverter/comicarchive.py
@@ -20,12 +20,13 @@
 
 from functools import cached_property, lru_cache
 import os
+from pathlib import Path
 import platform
 import distro
 from subprocess import STDOUT, PIPE, CalledProcessError
 from xml.dom.minidom import parseString
 from xml.parsers.expat import ExpatError
-from .shared import subprocess_run
+from .shared import IMAGE_TYPES, subprocess_run
 
 EXTRACTION_ERROR = 'Failed to extract archive. Try extracting file outside of KCC.'
 SEVENZIP = '7zz' if platform.system() == 'Darwin' else '7z'
@@ -65,6 +66,9 @@ class ComicArchive:
     def extract(self, targetdir):
         if not os.path.isdir(targetdir):
             raise OSError('Target directory doesn\'t exist.')
+        
+        if Path(self.basename).suffix.lower() in IMAGE_TYPES:
+            raise UserWarning('Put images into folder and drag and drop folder into KCC window.')
 
         missing = []
 
diff --git a/kindlecomicconverter/shared.py b/kindlecomicconverter/shared.py
index c6857d2..4a82f23 100644
--- a/kindlecomicconverter/shared.py
+++ b/kindlecomicconverter/shared.py
@@ -27,6 +27,9 @@ import sys
 from traceback import format_tb
 
 
+IMAGE_TYPES = ('.png', '.jpg', '.jpeg', '.gif', '.webp', '.jp2', '.avif')
+
+
 class HTMLStripper(HTMLParser):
     def __init__(self):
         HTMLParser.__init__(self)