diff --git a/scaffold.yml b/scaffold.yml
index 63e4278..3263f9a 100644
--- a/scaffold.yml
+++ b/scaffold.yml
@@ -3,6 +3,12 @@ vars:
   - type: string
     name: ProjectName
     description: Project Name
+    constraints:
+      - rule: Input == ""
+        message: The project name cannot be empty.
   - type: string
     name: ProjectNamespace
-    description: The Go module namespace
\ No newline at end of file
+    description: The Go module namespace
+    constraints:
+      - rule: Input == ""
+        message: The module namespace cannot be empty.