diff --git a/cachi2/core/resolver.py b/cachi2/core/resolver.py
index 331e93065..9b0df3e0e 100644
--- a/cachi2/core/resolver.py
+++ b/cachi2/core/resolver.py
@@ -30,19 +30,22 @@ def resolve_packages(request: Request) -> RequestOutput:
     """
     Resolve all packages specified in a request.
 
-    This function performs the operations in a working copy of the source directory to avoid
-    modifications.
+    This function performs the operations in a working copy of the source directory in case
+    a package manager that can make unwanted modifications will be used.
     """
-    original_source_dir = request.source_dir
+    if not request.yarn_packages:
+        return _resolve_packages(request)
+    else:
+        original_source_dir = request.source_dir
 
-    with TemporaryDirectory(".cachi2-source-copy", dir=".") as temp_dir:
-        source_backup = copy_directory(original_source_dir.path, Path(temp_dir).resolve())
+        with TemporaryDirectory(".cachi2-source-copy", dir=".") as temp_dir:
+            source_backup = copy_directory(original_source_dir.path, Path(temp_dir).resolve())
 
-        request.source_dir = RootedPath(source_backup)
-        output = _resolve_packages(request)
-        request.source_dir = original_source_dir
+            request.source_dir = RootedPath(source_backup)
+            output = _resolve_packages(request)
+            request.source_dir = original_source_dir
 
-        return output
+            return output
 
 
 def _resolve_packages(request: Request) -> RequestOutput:
diff --git a/tests/unit/test_resolver.py b/tests/unit/test_resolver.py
index c90e6b12c..c27afbdf3 100644
--- a/tests/unit/test_resolver.py
+++ b/tests/unit/test_resolver.py
@@ -100,21 +100,37 @@ def fetch(req: Request) -> RequestOutput:
     assert calls_by_pkgtype == ["gomod", "npm", "pip"]
 
 
+@pytest.mark.parametrize(
+    "packages, copy_exists",
+    [
+        ([{"type": "yarn"}], True),
+        ([{"type": "gomod"}, {"type": "pip"}, {"type": "npm"}], False),
+    ],
+)
 @mock.patch("cachi2.core.resolver._resolve_packages")
-def test_source_dir_copy(mock_resolve_packages: mock.Mock, tmp_path: Path) -> None:
+def test_source_dir_copy(
+    mock_resolve_packages: mock.Mock,
+    packages: list[dict[str, str]],
+    copy_exists: bool,
+    tmp_path: Path,
+) -> None:
     request = Request(
         source_dir=tmp_path,
         output_dir=tmp_path,
-        packages=[{"type": "yarn"}],
+        packages=packages,
     )
 
     def _resolve_packages(request: Request) -> None:
-        tmp_dir_name = request.source_dir.path.name
+        if copy_exists:
+            tmp_dir_name = request.source_dir.path.name
 
-        # assert a temporary directory is being used
-        assert tmp_dir_name != tmp_path.name
-        assert tmp_dir_name.startswith("tmp")
-        assert tmp_dir_name.endswith(".cachi2-source-copy")
+            # assert a temporary directory is being used
+            assert tmp_dir_name != tmp_path.name
+            assert tmp_dir_name.startswith("tmp")
+            assert tmp_dir_name.endswith(".cachi2-source-copy")
+        else:
+            # assert the original source_dir is being used
+            assert request.source_dir == RootedPath(tmp_path)
 
     mock_resolve_packages.side_effect = _resolve_packages