diff --git a/graphify/manifest_ingest.py b/graphify/manifest_ingest.py
index 717d9ad9a..0608eceb4 100644
--- a/graphify/manifest_ingest.py
+++ b/graphify/manifest_ingest.py
@@ -36,6 +36,31 @@
 
 _MAX_MANIFEST_BYTES = 2_000_000  # 2 MB cap — manifests are small; this rejects junk
 
+_TOMLI_REQUIRED = (
+    "Package-manifest ingestion on Python < 3.11 needs tomli. "
+    "Install with: pip install 'tomli' "
+    "(or reinstall graphifyy, which declares tomli for python_version < '3.11')."
+)
+
+
+def _load_toml_module():
+    """Return a tomllib-compatible module, or raise ImportError (#3283).
+
+    Returning ``None`` used to look identical to a virtual workspace root with
+    nothing to emit, so missing ``tomli`` on Python 3.10 silently dropped every
+    ``Cargo.toml`` / ``pyproject.toml``. Fail loud the way ``cargo_introspect``
+    already does.
+    """
+    try:
+        import tomllib as _toml  # type: ignore[import-not-found]
+        return _toml
+    except ImportError:
+        try:
+            import tomli as _toml  # type: ignore[import-not-found,no-redef]
+            return _toml
+        except ImportError as exc:
+            raise ImportError(_TOMLI_REQUIRED) from exc
+
 
 def is_package_manifest_path(path: Path) -> bool:
     """True if ``path`` is a recognized package manifest (by filename)."""
@@ -182,13 +207,7 @@ def _pep508_name(spec: str) -> str:
 
 
 def _parse_pyproject(text: str) -> dict | None:
-    try:
-        import tomllib as _toml
-    except ImportError:
-        try:
-            import tomli as _toml  # type: ignore
-        except ImportError:
-            return None
+    _toml = _load_toml_module()
     data = _toml.loads(text)
     proj = data.get("project", {}) if isinstance(data.get("project"), dict) else {}
     poetry = (data.get("tool", {}) or {}).get("poetry", {}) if isinstance(data.get("tool"), dict) else {}
@@ -207,13 +226,7 @@ def _parse_cargo(text: str) -> dict | None:
     """Cargo.toml: name/version from ``[package]``, runtime deps from
     ``[dependencies]`` plus every ``[target.<cfg>.dependencies]`` table (mirrors
     ``_parse_pyproject``'s runtime-only scope; dev-/build-dependencies excluded)."""
-    try:
-        import tomllib as _toml
-    except ImportError:  # pragma: no cover — Python < 3.11 without tomli only
-        try:
-            import tomli as _toml  # type: ignore
-        except ImportError:
-            return None
+    _toml = _load_toml_module()
     data = _toml.loads(text)
     pkg = data.get("package", {}) if isinstance(data.get("package"), dict) else {}
     name = pkg.get("name")
diff --git a/pyproject.toml b/pyproject.toml
index 7fd891dc8..c4d0b7a54 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -15,6 +15,7 @@ dependencies = [
     "networkx>=3.4",
     "numpy>=1.21",
     "rapidfuzz>=3.0",
+    "tomli>=2.0.1; python_version < '3.11'",
     "tree-sitter>=0.23.0,<0.26",
     "tree-sitter-python>=0.23,<0.26",
     "tree-sitter-javascript>=0.23,<0.26",
diff --git a/tests/test_manifest_tomli_required.py b/tests/test_manifest_tomli_required.py
new file mode 100644
index 000000000..982dc6782
--- /dev/null
+++ b/tests/test_manifest_tomli_required.py
@@ -0,0 +1,64 @@
+"""Regression tests for missing tomli on Python < 3.11 (#3283)."""
+from __future__ import annotations
+
+import builtins
+import sys
+from pathlib import Path
+
+import pytest
+
+from graphify.manifest_ingest import (
+    _TOMLI_REQUIRED,
+    _load_toml_module,
+    _parse_cargo,
+    _parse_pyproject,
+    extract_package_manifest,
+)
+
+
+def test_load_toml_module_raises_when_tomli_missing(monkeypatch):
+    real_import = builtins.__import__
+
+    def fake_import(name, *args, **kwargs):
+        if name in ("tomllib", "tomli"):
+            raise ImportError(f"blocked {name}")
+        return real_import(name, *args, **kwargs)
+
+    monkeypatch.setattr(builtins, "__import__", fake_import)
+    with pytest.raises(ImportError, match="tomli"):
+        _load_toml_module()
+
+
+def test_parse_pyproject_surfaces_missing_parser(monkeypatch):
+    monkeypatch.setattr(
+        "graphify.manifest_ingest._load_toml_module",
+        lambda: (_ for _ in ()).throw(ImportError(_TOMLI_REQUIRED)),
+    )
+    with pytest.raises(ImportError, match="tomli"):
+        _parse_pyproject('[project]\nname = "x"\n')
+
+
+def test_parse_cargo_surfaces_missing_parser(monkeypatch):
+    monkeypatch.setattr(
+        "graphify.manifest_ingest._load_toml_module",
+        lambda: (_ for _ in ()).throw(ImportError(_TOMLI_REQUIRED)),
+    )
+    with pytest.raises(ImportError, match="tomli"):
+        _parse_cargo('[package]\nname = "x"\nversion = "0.1.0"\n')
+
+
+def test_extract_package_manifest_reports_missing_tomli(tmp_path, monkeypatch):
+    p = tmp_path / "pyproject.toml"
+    p.write_text('[project]\nname = "cool"\nversion = "0.1"\n', encoding="utf-8")
+    monkeypatch.setattr(
+        "graphify.manifest_ingest._load_toml_module",
+        lambda: (_ for _ in ()).throw(ImportError(_TOMLI_REQUIRED)),
+    )
+    result = extract_package_manifest(p)
+    assert result["nodes"] == []
+    assert "tomli" in result.get("error", "").lower()
+
+
+@pytest.mark.skipif(sys.version_info >= (3, 11), reason="stdlib tomllib present")
+def test_tomli_is_importable_on_py310():
+    import tomli  # noqa: F401