diff --git a/doc/tutorial/basics/0_intro/47_validation.txt b/doc/tutorial/basics/0_intro/47_validation.txt
index 0f3c4fe..95ccb49 100644
--- a/doc/tutorial/basics/0_intro/47_validation.txt
+++ b/doc/tutorial/basics/0_intro/47_validation.txt
@@ -15,7 +15,7 @@
 They can be applied to CUE data, or directly to YAML or JSON.
 
 But constraints can also reduce boilerplate.
-If a constraints defines a concrete value, there is no need
+If a constraint defines a concrete value, there is no need
 to specify it in values to which this constraint applies.
 
 -- schema.cue --