diff --git a/fawltydeps/packages.py b/fawltydeps/packages.py
index 619954a3..dc3406f6 100644
--- a/fawltydeps/packages.py
+++ b/fawltydeps/packages.py
@@ -342,7 +342,7 @@ def pyenv_sources(*pyenv_paths: Path) -> Set[PyEnvSource]:
     for path in pyenv_paths:
         package_dirs = set(LocalPackageResolver.find_package_dirs(path))
         if not package_dirs:
-            logger.warning(f"Could not find a Python env at {path}!")
+            logger.debug(f"Could not find a Python env at {path}!")
         ret.update(PyEnvSource(d) for d in package_dirs)
     if pyenv_paths and not ret:
         raise ValueError(f"Could not find any Python env in {pyenv_paths}!")
diff --git a/fawltydeps/settings.py b/fawltydeps/settings.py
index 79dc2b93..c106dc2e 100644
--- a/fawltydeps/settings.py
+++ b/fawltydeps/settings.py
@@ -110,7 +110,7 @@ class Settings(BaseSettings):  # type: ignore
     output_format: OutputFormat = OutputFormat.HUMAN_SUMMARY
     code: Set[PathOrSpecial] = {Path(".")}
     deps: Set[Path] = {Path(".")}
-    pyenvs: Set[Path] = set()
+    pyenvs: Set[Path] = {Path(".")}
     custom_mapping: Optional[CustomMapping] = None
     ignore_undeclared: Set[str] = set()
     ignore_unused: Set[str] = set()
@@ -189,11 +189,17 @@ def create(cls, cmdline_args: argparse.Namespace) -> "Settings":
         if base_paths:
             code_paths = args_dict.setdefault("code", base_paths)
             deps_paths = args_dict.setdefault("deps", base_paths)
-            if code_paths != base_paths and deps_paths != base_paths:
+            pyenv_paths = args_dict.setdefault("pyenvs", base_paths)
+            if (
+                code_paths != base_paths
+                and deps_paths != base_paths
+                and pyenv_paths != base_paths
+            ):
                 msg = (
-                    "All three path specifications (code, deps, and base)"
-                    f"have been used. Use at most 2. basepaths={base_paths}, "
-                    f"code_paths={code_paths}, deps_paths={deps_paths}"
+                    "All four path specifications (code, deps, pyenvs, and base)"
+                    f"have been used. Use at most 3. basepaths={base_paths}, "
+                    f"code_paths={code_paths}, deps_paths={deps_paths}, "
+                    f"pyenv_paths={pyenv_paths}"
                 )
                 raise argparse.ArgumentError(argument=None, message=msg)
 
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index 3586bbee..cabd5a89 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -35,7 +35,7 @@ def make_json_settings_dict(**kwargs):
         "actions": ["check_undeclared", "check_unused"],
         "code": ["."],
         "deps": ["."],
-        "pyenvs": [],
+        "pyenvs": ["."],
         "custom_mapping": None,
         "output_format": "human_summary",
         "ignore_undeclared": [],
@@ -850,7 +850,7 @@ def test_cmdline_on_ignored_undeclared_option(
                 output_format = 'human_detailed'
                 # code = ['.']
                 deps = ['foobar']
-                # pyenvs = []
+                # pyenvs = ['.']
                 # ignore_undeclared = []
                 # ignore_unused = []
                 # deps_parser_choice = ...
diff --git a/tests/test_settings.py b/tests/test_settings.py
index 93629838..06a40d52 100644
--- a/tests/test_settings.py
+++ b/tests/test_settings.py
@@ -39,7 +39,7 @@
     actions={Action.REPORT_UNDECLARED, Action.REPORT_UNUSED},
     code={Path(".")},
     deps={Path(".")},
-    pyenvs=set(),
+    pyenvs={Path(".")},
     custom_mapping_file=set(),
     custom_mapping=None,
     output_format=OutputFormat.HUMAN_SUMMARY,
@@ -81,15 +81,15 @@ def _inner(**kwargs: str):
 
 safe_string = strategies.text(alphabet=string.ascii_letters + string.digits, min_size=1)
 nonempty_string_set = strategies.sets(safe_string, min_size=1)
-three_different_string_groups = strategies.tuples(
-    nonempty_string_set, nonempty_string_set, nonempty_string_set
-).filter(lambda ss: ss[0] != ss[1] and ss[0] != ss[2] and ss[1] != ss[2])
+four_different_string_groups = strategies.tuples(
+    *([nonempty_string_set] * 4),
+).filter(lambda ss: all(a != b for a, b in combinations(ss, 2)))
 
 
-@given(code_deps_base=three_different_string_groups)
-def test_code_deps_and_base_unequal__raises_error(code_deps_base):
-    code, deps, base = code_deps_base
-    args = list(base) + ["--code"] + list(code) + ["--deps"] + list(deps)
+@given(code_deps_pyenvs_base=four_different_string_groups)
+def test_code_deps_pyenvs_and_base_unequal__raises_error(code_deps_pyenvs_base):
+    code, deps, pyenvs, base = code_deps_pyenvs_base
+    args = [*base, "--code", *code, "--deps", *deps, "--pyenv", *pyenvs]
     with pytest.raises(argparse.ArgumentError):
         run_build_settings(args)
 
@@ -97,6 +97,7 @@ def test_code_deps_and_base_unequal__raises_error(code_deps_base):
 path_options = {  # options (-> settings members) that interact with basepath
     "--code": "code",
     "--deps": "deps",
+    "--pyenv": "pyenvs",
 }
 
 Item = TypeVar("Item")
@@ -151,13 +152,19 @@ def test_base_path_fills_path_options_when_other_path_settings_are_absent(basepa
         pytest.param(conf_sett, base, id=test_name)
         for conf_sett, base, test_name in [
             (None, {"single-base"}, "empty-config"),
-            (dict(code=["test-code"]), {"base1", "base2"}, "only-code-set"),
-            (dict(deps=["deps-test"]), {"single-base"}, "only-deps-set"),
+            ({"code": ["test-code"]}, {"base1", "base2"}, "only-code-set"),
+            ({"deps": ["deps-test"]}, {"single-base"}, "only-deps-set"),
+            ({"pyenvs": ["pyenvs-test"]}, {"single-base"}, "only-pyenvs-set"),
             (
-                dict(code=["code-test"], deps=["test-deps"]),
+                {"code": ["code-test"], "deps": ["test-deps"]},
                 {"base1", "base2"},
                 "code-and-deps-set",
             ),
+            (
+                {"code": ["code-test"], "deps": ["test-deps"], "pyenvs": ["abc"]},
+                {"base1", "base2"},
+                "all-three-set",
+            ),
         ]
     ],
 )