diff --git a/komodo/cli.py b/komodo/cli.py
index 6b547b298..1211920a3 100755
--- a/komodo/cli.py
+++ b/komodo/cli.py
@@ -54,9 +54,7 @@ def _main(args):
     data = Data(extra_data_dirs=args.extra_data_dirs)
 
     if args.download or (not args.build and not args.install):
-        git_hashes = fetch(
-            args.pkgs, args.repo, outdir=args.workspace_for_downloads, pip=args.pip
-        )
+        git_hashes = fetch(args.pkgs, args.repo, outdir=args.downloads, pip=args.pip)
 
     if args.download and not args.build:
         sys.exit(0)
@@ -72,7 +70,7 @@ def _main(args):
             args.repo,
             data,
             prefix=str(tmp_prefix),
-            dlprefix=args.workspace_for_downloads,
+            dlprefix=args.downloads,
             builddir=args.tmp,
             jobs=args.jobs,
             cmk=args.cmake,
@@ -162,8 +160,9 @@ def _main(args):
             "--no-index",
             "--no-deps",
             "--ignore-installed",
-            f"--cache-dir {args.workspace_for_downloads}",
-            f"--find-links {args.workspace_for_downloads}",
+            # assuming fetch.py has done "pip download" to this directory:
+            f"--cache-dir {args.downloads}",
+            f"--find-links {args.downloads}",
         ]
         shell_input.append(current.get("makeopts"))
 
@@ -268,14 +267,14 @@ def parse_args(args: List[str]) -> argparse.Namespace:
         "current working directory.",
     )
     optional_args.add_argument(
-        "--workspace_for_downloads",
+        "--downloads",
         "--cache",  # deprecated
         "-c",  # deprecated
         type=str,
-        default="_work",
+        default="downloads",
         help="A temporary destination directory used for downloads, "
         "used by pip download, cp, rsync and git clone. This directory "
-        "should be empty if it already exists, otherwise it will be created.",
+        "must be empty if it already exists, otherwise it will be created.",
     )
     optional_args.add_argument(
         "--jobs",
diff --git a/komodo/fetch.py b/komodo/fetch.py
index f7d7e9aec..530e3cfdb 100644
--- a/komodo/fetch.py
+++ b/komodo/fetch.py
@@ -74,9 +74,8 @@ def fetch(pkgs, repo, outdir, pip="pip") -> dict:
             "cannot be None or the empty string."
         )
     if os.path.exists(outdir) and os.listdir(outdir):
-        print(
-            f"WARNING: Downloading to non-empty directory {outdir}, "
-            "this is not recommended."
+        raise RuntimeError(
+            f"Downloading to non-empty directory {outdir} is not supported."
         )
     if not os.path.exists(outdir):
         os.mkdir(outdir)
@@ -176,7 +175,8 @@ def fetch(pkgs, repo, outdir, pip="pip") -> dict:
         "-o",
         type=str,
         required=True,
-        help="The download destination for pip, cp, rsync and git; will be created.",
+        help="The download destination for pip, cp, rsync and git. "
+        "Must be non-existing or empty.",
     )
     parser.add_argument(
         "--pip",