diff --git a/roles/custom/matrix-dendrite/defaults/main.yml b/roles/custom/matrix-dendrite/defaults/main.yml
index 8688965d4..0ef646cfe 100644
--- a/roles/custom/matrix-dendrite/defaults/main.yml
+++ b/roles/custom/matrix-dendrite/defaults/main.yml
@@ -212,5 +212,9 @@ matrix_dendrite_userapi_auto_join_rooms: []
 # name, number of active users and some information on your deployment config.
 matrix_dendrite_report_stats: false
 
-# Configuration for the full-text search engine.
+# Contorls whether thumbnails for media content are generated dynamically
+matrix_dendrite_mediaapi_dynamic_thumbnails: false
+matrix_dendrite_mediaapi_max_thumbnail_generators: 10
+
+# Controls whether the full-text search engine is enabled
 matrix_dendrite_syncapi_search_enabled: false
diff --git a/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2 b/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
index 8e91ae6c9..dd92e7f55 100644
--- a/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
+++ b/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
@@ -293,10 +293,10 @@ media_api:
   max_file_size_bytes: {{ matrix_dendrite_max_file_size_bytes|to_json }}
 
   # Whether to dynamically generate thumbnails if needed.
-  dynamic_thumbnails: false
+  dynamic_thumbnails: {{ matrix_dendrite_mediaapi_dynamic_thumbnails|to_json }}
 
   # The maximum number of simultaneous thumbnail generators to run.
-  max_thumbnail_generators: 10
+  max_thumbnail_generators: {{ matrix_dendrite_mediaapi_max_thumbnails_generators|to_json }}
 
   # A list of thumbnail sizes to be generated for media content.
   thumbnail_sizes: