diff --git a/esmvalcore/cmor/table.py b/esmvalcore/cmor/table.py
index aea873a9de..ebce5431ae 100644
--- a/esmvalcore/cmor/table.py
+++ b/esmvalcore/cmor/table.py
@@ -124,9 +124,17 @@ def read_cmor_tables(cfg_developer: Optional[Path] = None) -> None:
     ----------
     cfg_developer:
         Path to config-developer.yml file.
+
+    Raises
+    ------
+    TypeError
+        If `cfg_developer` is not a Path-like object
     """
     if cfg_developer is None:
         cfg_developer = Path(__file__).parents[1] / 'config-developer.yml'
+    elif not isinstance(cfg_developer, Path):
+        raise TypeError("cfg_developer is not a Path-like object, got ",
+                        cfg_developer)
     mtime = cfg_developer.stat().st_mtime
     cmor_tables = _read_cmor_tables(cfg_developer, mtime)
     CMOR_TABLES.clear()
diff --git a/tests/integration/cmor/test_read_cmor_tables.py b/tests/integration/cmor/test_read_cmor_tables.py
index 4a50e2c76f..32a472b316 100644
--- a/tests/integration/cmor/test_read_cmor_tables.py
+++ b/tests/integration/cmor/test_read_cmor_tables.py
@@ -1,5 +1,6 @@
 from pathlib import Path
 
+import pytest
 import yaml
 
 from esmvalcore.cmor.table import CMOR_TABLES
@@ -18,6 +19,14 @@
 }
 
 
+def test_read_cmor_tables_raiser():
+    """Test func raiser."""
+    cfg_file = {"cow": "moo"}
+    with pytest.raises(TypeError) as exc:
+        read_cmor_tables(cfg_file)
+        assert "cow" in str(exc)
+
+
 def test_read_cmor_tables():
     """Test that the function `read_cmor_tables` loads the tables correctly."""
     table_path = Path(root).parent / 'tables'