diff --git a/docs/project_preview.md b/docs/project_preview.md
index c70cc8f..5981c26 100644
--- a/docs/project_preview.md
+++ b/docs/project_preview.md
@@ -4,9 +4,7 @@
 
 * Author: {author}
 * Description: {description}
-* [Extra docs]({doc_link})
-* Clock: {clock_hz} Hz
-* External hardware: {external_hw}
+* Language: {language}
 
 ### How it works
 
diff --git a/documentation.py b/documentation.py
index ef3a06e..423ee40 100644
--- a/documentation.py
+++ b/documentation.py
@@ -11,7 +11,7 @@ import cairosvg
 # makes sure that the basic info is present
 def check_yaml_docs(yaml):
     logging.info("checking docs")
-    for key in ['author', 'title', 'description', 'how_it_works', 'how_to_test', 'language']:
+    for key in ['author', 'title', 'description', 'how_it_works', 'how_to_test', 'language', 'inputs', 'outputs']:
         if key not in yaml['documentation']:
             logging.error("missing key {} in documentation".format(key))
             exit(1)