diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e369d3..d323cc2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+* Fixed `Base.to_dict()` to recursively pass down convert_type_defination.
+
 ### Removed
 
 
diff --git a/src/compas_ifc/entities/base.py b/src/compas_ifc/entities/base.py
index 1a6986e..48daa8c 100644
--- a/src/compas_ifc/entities/base.py
+++ b/src/compas_ifc/entities/base.py
@@ -165,7 +165,7 @@ def iter_list(values):
             _values = []
             for value in values:
                 if isinstance(value, Base):
-                    value = value.to_dict(recursive=recursive, ignore_fields=ignore_fields, include_fields=include_fields)
+                    value = value.to_dict(recursive=recursive, ignore_fields=ignore_fields, include_fields=include_fields, convert_type_definitions=convert_type_definitions)
                 elif convert_type_definitions and isinstance(value, TypeDefinition):
                     value = value.value
                 elif isinstance(value, (list, tuple)):
@@ -184,7 +184,7 @@ def iter_list(values):
             value = getattr(self, key)
 
             if recursive and isinstance(value, Base):
-                value = value.to_dict(recursive=recursive, ignore_fields=ignore_fields, include_fields=include_fields)
+                value = value.to_dict(recursive=recursive, ignore_fields=ignore_fields, include_fields=include_fields, convert_type_definitions=convert_type_definitions)
             elif recursive and isinstance(value, (list, tuple)):
                 value = iter_list(value)
             elif convert_type_definitions and isinstance(value, TypeDefinition):