diff --git a/tools/schemacode/bidsschematools/tests/test_schema.py b/tools/schemacode/bidsschematools/tests/test_schema.py
index 5e7b0e3575..bd5fc28942 100644
--- a/tools/schemacode/bidsschematools/tests/test_schema.py
+++ b/tools/schemacode/bidsschematools/tests/test_schema.py
@@ -343,3 +343,16 @@ def test_dereferencing():
             },
         },
     }
+
+
+def test_namespace_to_dict():
+
+    def check_for_namespaces(obj):
+        if isinstance(obj, dict):
+            [check_for_namespaces(val) for val in obj.values()]
+        elif isinstance(obj, list):
+            [check_for_namespaces(val) for val in obj]
+        elif isinstance(obj, types.Namespace):
+            raise ValueError("Namespace object found in dict")
+
+    check_for_namespaces(schema.load_schema().to_dict())
diff --git a/tools/schemacode/bidsschematools/types/namespace.py b/tools/schemacode/bidsschematools/types/namespace.py
index 39943ac3f0..e2c37eee40 100644
--- a/tools/schemacode/bidsschematools/types/namespace.py
+++ b/tools/schemacode/bidsschematools/types/namespace.py
@@ -168,12 +168,17 @@ def __init__(self, *args, **kwargs):
         self._properties = dict(*args, **kwargs)
 
     def to_dict(self) -> dict:
-        ret = {}
-        for key, val in self._properties.items():
-            if isinstance(val, Namespace):
-                val = val.to_dict()
-            ret[key] = val
-        return ret
+
+        def _to_dict(obj):
+            if isinstance(obj, Namespace):
+                return {k: _to_dict(v) for k, v in obj._properties.items()}
+            if isinstance(obj, list):
+                return [_to_dict(v) for v in obj]
+            if isinstance(obj, dict):
+                return {k: _to_dict(v) for k, v in obj.items()}
+            return obj
+
+        return _to_dict(self)
 
     def __deepcopy__(self, memo):
         return self.build(self.to_dict())