diff --git a/utils/dartdevc/BUILD.gn b/utils/dartdevc/BUILD.gn
index 32b51a71b7d..f9777d1481d 100644
--- a/utils/dartdevc/BUILD.gn
+++ b/utils/dartdevc/BUILD.gn
@@ -26,8 +26,7 @@ application_snapshot("dartdevc") {
 
   training_args = [
     "--dart-sdk-summary",
-    rebase_path(sdk_outline_unsound_dill),
-    "--no-sound-null-safety",
+    rebase_path(sdk_outline_sound_dill),
     "-o",
     "dartdevc.js",
     rebase_path("../../pkg/dev_compiler/bin/dartdevc.dart"),
@@ -37,12 +36,8 @@ application_snapshot("dartdevc") {
     training_args += [ "--canary" ]
   }
 
-  deps = [
-    ":dartdevc_kernel_sdk",
-    ":dartdevc_platform_unsound",
-  ]
-
-  inputs = [ sdk_outline_unsound_dill ]
+  deps = [ ":dartdevc_platform_sound" ]
+  inputs = [ sdk_outline_sound_dill ]
 }
 
 sdk_root = "../../sdk"