diff --git a/src/debugpy/server/cli.py b/src/debugpy/server/cli.py
index ff117094..56974891 100644
--- a/src/debugpy/server/cli.py
+++ b/src/debugpy/server/cli.py
@@ -218,7 +218,8 @@ def parse_args():
     parse_args_from_command_line(seen)
     parse_args_from_environment(seen)
 
-    if options.target is None:
+    # if the target is not set, or is empty, this is an error
+    if options.target is None or not options.target.strip():
         raise ValueError("missing target: " + TARGET)
 
     if options.mode is None:
@@ -228,7 +229,6 @@ def parse_args():
     if options.target_kind == "pid" and options.wait_for_client:
         raise ValueError("--pid does not support --wait-for-client")
 
-    assert options.target is not None
     assert options.target_kind is not None
     assert options.address is not None
 
diff --git a/tests/debugpy/server/test_cli.py b/tests/debugpy/server/test_cli.py
index 141d3266..28bda085 100644
--- a/tests/debugpy/server/test_cli.py
+++ b/tests/debugpy/server/test_cli.py
@@ -180,7 +180,7 @@ def test_address_required(cli):
 
 def test_missing_target(cli):
     with pytest.raises(ValueError) as ex:
-        cli(["--listen", "8888"])
+        cli(["--listen", "8888", "-m", ""])
     
     assert "missing target" in str(ex.value)