diff --git a/changelog.md b/changelog.md
index b6caa5050..59780d907 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,6 +1,7 @@
 # changelog
 
 ## Unreleased
+* `FIX` Fix a typo in `no-unknown` diagnostic message
 <!-- Add all new changes here. They will be moved under a version at release -->
 
 ## 3.16.0
diff --git a/locale/en-us/script.lua b/locale/en-us/script.lua
index f8a38b9ab..1c7c29272 100644
--- a/locale/en-us/script.lua
+++ b/locale/en-us/script.lua
@@ -89,7 +89,7 @@ DIAG_COSE_NON_OBJECT    =
 DIAG_COUNT_DOWN_LOOP    =
 'Do you mean `{}` ?'
 DIAG_UNKNOWN            =
-'Can not infer type.'
+'Cannot infer type.'
 DIAG_DEPRECATED         =
 'Deprecated.'
 DIAG_DIFFERENT_REQUIRES =