diff --git a/Mergin/plugin.py b/Mergin/plugin.py
index cd81f52b..c53ab1ab 100644
--- a/Mergin/plugin.py
+++ b/Mergin/plugin.py
@@ -67,9 +67,28 @@
 from .processing.provider import MerginProvider
 import processing
 
+from pyplugin_installer.installer import QgsPluginInstaller
+
 MERGIN_CLIENT_LOG = os.path.join(QgsApplication.qgisSettingsDirPath(), "mergin-client-log.txt")
 os.environ["MERGIN_CLIENT_LOG"] = MERGIN_CLIENT_LOG
 
+# store method that will be monkeypatched
+_original_method = QgsPluginInstaller.installPlugin
+
+
+def install_plugin(self, key, quiet=False, stable=True):
+    """
+    On Windows we need to release lock on geodiff library and unload plugin before
+    performing an update. See https://github.com/MerginMaps/qgis-mergin-plugin/issues/504
+    and https://github.com/MerginMaps/geodiff/issues/205
+    """
+    if key == "Mergin" and os.name == "nt":
+        from qgis.utils import unloadPlugin
+
+        unloadPlugin(key)
+
+    _original_method(self, key, quiet, stable)
+
 
 class MerginPlugin:
     def __init__(self, iface):
@@ -185,6 +204,11 @@ def initGui(self):
 
         QgsProject.instance().layersAdded.connect(self.add_context_menu_actions)
 
+        # monkeypatch plugin installer to allow unlocking geodiff library and unloading plugin before installing
+        # see https://github.com/MerginMaps/qgis-mergin-plugin/issues/504, https://github.com/MerginMaps/geodiff/issues/205
+        if os.name == "nt":
+            QgsPluginInstaller.installPlugin = install_plugin
+
     def add_action(
         self,
         icon_name,
@@ -547,6 +571,16 @@ def unload(self):
 
         QgsApplication.processingRegistry().removeProvider(self.provider)
 
+        # unlock geodiff library and revert monkeypatching
+        if os.name == "nt":
+            from _ctypes import FreeLibrary
+            from .mergin.deps import pygeodiff
+
+            geodiff = pygeodiff.GeoDiff()
+            FreeLibrary(geodiff.clib.lib._handle)
+
+        QgsPluginInstaller.installPlugin = _original_method
+
     def view_local_changes(self):
         project_path = QgsProject.instance().homePath()
         if not project_path: