diff --git a/x4.md b/x4.md
index 8f3e755..9ee9af1 100644
--- a/x4.md
+++ b/x4.md
@@ -123,7 +123,7 @@ TODO
 
 ## Dependencies between layers
 
-As it was mentioned above, there are cases when two layers dependen on one another:
+As it was mentioned above, there are cases when two layers depend on one another:
 * encrypting messages is done by the privacy layer instead of security layer
 * the privacy layer needs to know some details of the payload to properly route it.