--- a/src/eric7/EricWidgets/EricSingleApplication.py	Mon Feb 19 19:17:04 2024 +0100
+++ b/src/eric7/EricWidgets/EricSingleApplication.py	Wed Feb 21 10:56:24 2024 +0100
@@ -122,9 +122,9 @@
         for filename in args.file_or_project:
             ext = os.path.normcase(os.path.splitext(filename)[1])
 
-            if ext in (".epj", ".e4p"):
+            if ext in (".epj",):
                 self.__openProject(filename)
-            elif ext in (".emj", ".e4m", ".e5m"):
+            elif ext in (".emj",):
                 self.__openMultiProject(filename)
             else:
                 self.__openFile(filename)