diff --git a/ui/build/kati.go b/ui/build/kati.go
index 1494688f0..7635c10ce 100644
--- a/ui/build/kati.go
+++ b/ui/build/kati.go
@@ -85,7 +85,7 @@ func runKati(ctx Context, config Config) {
 
 	// PDK builds still uses a few implicit rules
 	if !config.IsPdkBuild() {
-		args = append(args, "--warn_implicit_rules")
+		args = append(args, "--werror_implicit_rules")
 	}
 
 	if !config.BuildBrokenDupRules() {