diff --git a/cpdctrl_gui/main.py b/cpdctrl_gui/main.py
index bc6e571..e0af061 100644
--- a/cpdctrl_gui/main.py
+++ b/cpdctrl_gui/main.py
@@ -2,11 +2,13 @@ import sys
 if __name__ == "__main__":
     if __package__ is None:
         # make relative imports work as described here: https://peps.python.org/pep-0366/#proposed-change
-        __package__ = "cpdctrl"
+        __package__ = "cpdctrl_gui"
         from os import path
         filepath = path.realpath(path.abspath(__file__))
-        pdir = path.dirname(path.dirname(filepath))
-        sys.path.insert(0, pdir)
+        # Make sure both projects are loaded from the source tree instead of installed packages
+        # parent dir of both projects
+        pdir = path.dirname(path.dirname(path.dirname(filepath)))
+        sys.path.insert(0, path.join(pdir, "cpdctrl-gui"))
         sys.path.insert(0, path.join(pdir, "cpdctrl"))
 print(sys.path)
 from cpdctrl_gui import init