diff --git a/.gitignore b/.gitignore
index 2f4ae33..cdffe91 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 # DeepLC
 data/
-*.png
+./*.png
 *.pyc
 datasets/an_data.csv
 datasets/integrated_dataset_filtered.csv
diff --git a/deeplc/gui.py b/deeplc/gui.py
index d585ec3..36ee9f3 100644
--- a/deeplc/gui.py
+++ b/deeplc/gui.py
@@ -1,23 +1,25 @@
 """Graphical user interface."""
+from multiprocessing import freeze_support
+from pathlib import Path
 import importlib.resources
 
 from gooey import Gooey, local_resource_path
 
-from deeplc import package_data
+import deeplc.package_data.gui_images as img_module
 from deeplc.__main__ import main
 
 
-with importlib.resources.path(package_data, "gui_images") as img_dir:
-    _IMG_DIR = img_dir
+# Get path to package_data/images
+# Workaround with parent of specific file required for Python 3.9+ support
+with importlib.resources.path(img_module, 'config_icon.png') as resource:
+    _IMG_DIR = Path(resource).parent
 
 
 @Gooey(
     program_name="DeepLC",
     image_dir=local_resource_path(_IMG_DIR),
     tabbed_groups=True,
-    default_size=(760, 720),
-    target="deeplc",
-    suppress_gooey_flag=True,
+    default_size=(720, 480),
     monospace_display=True,
 )
 def start_gui():
@@ -25,4 +27,5 @@ def start_gui():
     main(gui=True)
 
 if __name__ == "__main__":
+    freeze_support()  # Required for multiprocessing with PyInstaller
     start_gui()
diff --git a/deeplc/package_data/gui_images/__init__.py b/deeplc/package_data/gui_images/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/deeplc/package_data/gui_images/config_icon.png b/deeplc/package_data/gui_images/config_icon.png
new file mode 100644
index 0000000..1fa72e1
Binary files /dev/null and b/deeplc/package_data/gui_images/config_icon.png differ
diff --git a/deeplc/package_data/gui_images/program_icon.png b/deeplc/package_data/gui_images/program_icon.png
new file mode 100644
index 0000000..770e0ee
Binary files /dev/null and b/deeplc/package_data/gui_images/program_icon.png differ
diff --git a/img/deeplc.icns b/img/deeplc.icns
new file mode 100644
index 0000000..564e540
Binary files /dev/null and b/img/deeplc.icns differ
diff --git a/img/deeplc.ico b/img/deeplc.ico
new file mode 100644
index 0000000..094b3a4
Binary files /dev/null and b/img/deeplc.ico differ