diff --git a/lectern/contrib/relative_location.py b/lectern/contrib/relative_location.py
index f606b94..28f6bc5 100644
--- a/lectern/contrib/relative_location.py
+++ b/lectern/contrib/relative_location.py
@@ -30,7 +30,7 @@ def __call__(
         fragment: Fragment,
         directives: Mapping[str, Directive],
     ) -> Fragment:
-        if isinstance(directives[fragment.directive], NamespacedResourceDirective):
+        if isinstance(directives.get(fragment.directive), NamespacedResourceDirective):
             name = fragment.expect("name")
             if ":" not in name:
                 fragment = replace(fragment, arguments=[self.ctx.generate.path(name)])
diff --git a/lectern/contrib/yaml_to_json.py b/lectern/contrib/yaml_to_json.py
index 5a82ccb..ad4573b 100644
--- a/lectern/contrib/yaml_to_json.py
+++ b/lectern/contrib/yaml_to_json.py
@@ -29,7 +29,7 @@ def beet_default(ctx: Context):
 
 def handle_yaml(fragment: Fragment, directives: Mapping[str, Directive]) -> Fragment:
     """Loader that converts yaml to json."""
-    directive = directives[fragment.directive]
+    directive = directives.get(fragment.directive)
     is_yaml = False
 
     if isinstance(directive, NamespacedResourceDirective):