diff --git a/modulemd/v2/include/modulemd-2.0/modulemd-component-module.h b/modulemd/v2/include/modulemd-2.0/modulemd-component-module.h
index 9e86af3dd..51165fc9a 100644
--- a/modulemd/v2/include/modulemd-2.0/modulemd-component-module.h
+++ b/modulemd/v2/include/modulemd-2.0/modulemd-component-module.h
@@ -49,7 +49,7 @@ modulemd_component_module_new (const gchar *key);
 /**
  * modulemd_component_module_set_ref:
  * @self: This #ModulemdComponentModule object.
- * @ref: The commit ID in the SCM repository.
+ * @ref: (in) (nullable): The commit ID in the SCM repository.
  *
  * Since: 2.0
  */
@@ -73,7 +73,7 @@ modulemd_component_module_get_ref (ModulemdComponentModule *self);
 /**
  * modulemd_component_module_set_repository:
  * @self: This #ModulemdComponentModule object
- * @repository: The URI of the SCM repository.
+ * @repository: (in) (nullable): The URI of the SCM repository.
  *
  * Since: 2.0
  */
diff --git a/modulemd/v2/include/modulemd-2.0/modulemd-component-rpm.h b/modulemd/v2/include/modulemd-2.0/modulemd-component-rpm.h
index 2257fb362..d4f9d714a 100644
--- a/modulemd/v2/include/modulemd-2.0/modulemd-component-rpm.h
+++ b/modulemd/v2/include/modulemd-2.0/modulemd-component-rpm.h
@@ -126,7 +126,7 @@ modulemd_component_rpm_get_multilib_arches_as_strv (
 /**
  * modulemd_component_rpm_set_cache:
  * @self: This #ModulemdComponentRpm object.
- * @cache: The lookaside cache URL.
+ * @cache: (in) (nullable): The lookaside cache URL.
  *
  * Since: 2.0
  */
@@ -150,7 +150,7 @@ modulemd_component_rpm_get_cache (ModulemdComponentRpm *self);
 /**
  * modulemd_component_rpm_set_ref:
  * @self: This #ModulemdComponentRpm object.
- * @ref: The commit ID in the SCM repository.
+ * @ref: (in) (nullable): The commit ID in the SCM repository.
  *
  * Since: 2.0
  */
@@ -173,7 +173,7 @@ modulemd_component_rpm_get_ref (ModulemdComponentRpm *self);
 /**
  * modulemd_component_rpm_set_repository:
  * @self: This #ModulemdComponentRpm object
- * @repository: The URI of the SCM repository.
+ * @repository: (in) (nullable): The URI of the SCM repository.
  *
  * Since: 2.0
  */
diff --git a/modulemd/v2/include/modulemd-2.0/modulemd-component.h b/modulemd/v2/include/modulemd-2.0/modulemd-component.h
index ed971c3e1..24e746707 100644
--- a/modulemd/v2/include/modulemd-2.0/modulemd-component.h
+++ b/modulemd/v2/include/modulemd-2.0/modulemd-component.h
@@ -213,7 +213,8 @@ modulemd_component_get_key (ModulemdComponent *self);
 /**
  * modulemd_component_set_rationale:
  * @self: This #ModulemdComponent object
- * @rationale: The reason that this component is part of the stream.
+ * @rationale: (in) (nullable): The reason that this component is part of the
+ * stream.
  *
  * Since: 2.0
  */