diff --git a/gns3server/controller/__init__.py b/gns3server/controller/__init__.py
index 5113cfb0..05b0dfe2 100644
--- a/gns3server/controller/__init__.py
+++ b/gns3server/controller/__init__.py
@@ -29,7 +29,7 @@ except ImportError:
     from importlib import resources as importlib_resources
 
 from ..config import Config
-from ..utils import parse_version
+from ..utils import parse_version, md5sum
 from ..utils.images import default_images_directory
 
 from .project import Project
@@ -289,12 +289,21 @@ class Controller:
         except OSError as e:
             log.error(str(e))
 
+
     @staticmethod
-    def install_resource_files(dst_path, resource_name):
+    def install_resource_files(dst_path, resource_name, upgrade_resources=True):
         """
         Install files from resources to user's file system
         """
 
+        def should_copy(src, dst, upgrade_resources):
+            if not os.path.exists(dst):
+                return True
+            if upgrade_resources is False:
+                return False
+            # copy the resource if it is different
+            return md5sum(src) != md5sum(dst)
+
         if hasattr(sys, "frozen") and sys.platform.startswith("win"):
             resource_path = os.path.normpath(os.path.join(os.path.dirname(sys.executable), resource_name))
             for filename in os.listdir(resource_path):
@@ -303,7 +312,7 @@ class Controller:
         else:
             for entry in importlib_resources.files('gns3server').joinpath(resource_name).iterdir():
                 full_path = os.path.join(dst_path, entry.name)
-                if entry.is_file() and not os.path.exists(full_path):
+                if entry.is_file() and should_copy(str(entry), full_path, upgrade_resources):
                     log.debug(f'Installing {resource_name} resource file "{entry.name}" to "{full_path}"')
                     shutil.copy(str(entry), os.path.join(dst_path, entry.name))
                 elif entry.is_dir():
@@ -319,7 +328,7 @@ class Controller:
         dst_path = self.configs_path()
         log.info(f"Installing base configs in '{dst_path}'")
         try:
-            Controller.install_resource_files(dst_path, "configs")
+            Controller.install_resource_files(dst_path, "configs", upgrade_resources=False)
         except OSError as e:
             log.error(f"Could not install base config files to {dst_path}: {e}")
 
@@ -332,7 +341,7 @@ class Controller:
         dst_path = self.disks_path()
         log.info(f"Installing built-in disks in '{dst_path}'")
         try:
-            Controller.install_resource_files(dst_path, "disks")
+            Controller.install_resource_files(dst_path, "disks", upgrade_resources=False)
         except OSError as e:
             log.error(f"Could not install disk files to {dst_path}: {e}")
 
diff --git a/gns3server/controller/appliance_manager.py b/gns3server/controller/appliance_manager.py
index 39012129..9607f629 100644
--- a/gns3server/controller/appliance_manager.py
+++ b/gns3server/controller/appliance_manager.py
@@ -82,7 +82,7 @@ class ApplianceManager:
         os.makedirs(appliances_path, exist_ok=True)
         return appliances_path
 
-    def builtin_appliances_path(self, delete_first=False):
+    def builtin_appliances_path(self):
         """
         Get the built-in appliance storage directory
         """
@@ -91,8 +91,6 @@ class ApplianceManager:
         appname = vendor = "GNS3"
         resources_path = os.path.expanduser(server_config.get("resources_path", platformdirs.user_data_dir(appname, vendor, roaming=True)))
         appliances_dir = os.path.join(resources_path, "appliances")
-        if delete_first:
-            shutil.rmtree(appliances_dir, ignore_errors=True)
         os.makedirs(appliances_dir, exist_ok=True)
         return appliances_dir
 
@@ -101,7 +99,7 @@ class ApplianceManager:
         At startup we copy the built-in appliances files.
         """
 
-        dst_path = self.builtin_appliances_path(delete_first=True)
+        dst_path = self.builtin_appliances_path()
         log.info(f"Installing built-in appliances in '{dst_path}'")
         from . import Controller
         try:
diff --git a/gns3server/utils/__init__.py b/gns3server/utils/__init__.py
index 3740066b..0ee4377a 100644
--- a/gns3server/utils/__init__.py
+++ b/gns3server/utils/__init__.py
@@ -23,6 +23,7 @@ import textwrap
 import posixpath
 import socket
 import errno
+import hashlib
 
 
 def force_unix_path(path):
@@ -120,3 +121,14 @@ def is_ipv6_enabled() -> bool:
         if e.errno == errno.EADDRINUSE:
             return True
         raise
+
+def md5sum(filename):
+    """
+    Calculate the MD5 checksum of a file.
+    """
+
+    hash_md5 = hashlib.md5()
+    with open(filename, "rb") as f:
+        for chunk in iter(lambda: f.read(4096), b""):
+            hash_md5.update(chunk)
+    return hash_md5.hexdigest()
diff --git a/requirements.txt b/requirements.txt
index 9a94f5ce..398250ca 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,6 +8,6 @@ psutil>=6.1.0
 async-timeout>=4.0.3,<4.1
 distro>=1.9.0
 py-cpuinfo>=9.0.0,<10.0
-platformdirs>=2.4.0
+platformdirs>=2.4.0,<3  # platformdirs >=3 conflicts when building Debian packages
 importlib-resources>=1.3; python_version < '3.9'
 truststore>=0.10.0; python_version >= '3.10'