diff --git a/changelogs/fragments/6074-loader_in_listify.yml.yml b/changelogs/fragments/6074-loader_in_listify.yml.yml
new file mode 100644
index 0000000000..3c01cde754
--- /dev/null
+++ b/changelogs/fragments/6074-loader_in_listify.yml.yml
@@ -0,0 +1,2 @@
+minor_changes:
+  - cartesian and flattened lookup plugins - adjust to parameter deprecation in ansible-core 2.14's ``listify_lookup_plugin_terms`` helper function (https://github.com/ansible-collections/community.general/pull/6074).
diff --git a/plugins/lookup/cartesian.py b/plugins/lookup/cartesian.py
index d76e8f532a..d63f3943b0 100644
--- a/plugins/lookup/cartesian.py
+++ b/plugins/lookup/cartesian.py
@@ -66,7 +66,12 @@ class LookupModule(LookupBase):
         """
         results = []
         for x in terms:
-            intermediate = listify_lookup_plugin_terms(x, templar=self._templar, loader=self._loader)
+            try:
+                intermediate = listify_lookup_plugin_terms(x, templar=self._templar)
+            except TypeError:
+                # The loader argument is deprecated in ansible-core 2.14+. Fall back to
+                # pre-2.14 behavior for older ansible-core versions.
+                intermediate = listify_lookup_plugin_terms(x, templar=self._templar, loader=self._loader)
             results.append(intermediate)
         return results
 
diff --git a/plugins/lookup/flattened.py b/plugins/lookup/flattened.py
index 0f290e559d..e955b6478e 100644
--- a/plugins/lookup/flattened.py
+++ b/plugins/lookup/flattened.py
@@ -67,7 +67,12 @@ class LookupModule(LookupBase):
 
             if isinstance(term, string_types):
                 # convert a variable to a list
-                term2 = listify_lookup_plugin_terms(term, templar=self._templar, loader=self._loader)
+                try:
+                    term2 = listify_lookup_plugin_terms(term, templar=self._templar)
+                except TypeError:
+                    # The loader argument is deprecated in ansible-core 2.14+. Fall back to
+                    # pre-2.14 behavior for older ansible-core versions.
+                    term2 = listify_lookup_plugin_terms(term, templar=self._templar, loader=self._loader)
                 # but avoid converting a plain string to a list of one string
                 if term2 != [term]:
                     term = term2