diff --git a/ui/build/config.go b/ui/build/config.go
index a755d14..b746cf8 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -313,8 +313,9 @@
 
 func NewConfig(ctx Context, args ...string) Config {
 	ret := &configImpl{
-		environ:       OsEnvironment(),
-		sandboxConfig: &SandboxConfig{},
+		environ:               OsEnvironment(),
+		sandboxConfig:         &SandboxConfig{},
+		ninjaWeightListSource: HINT_FROM_SOONG,
 	}
 
 	// Default matching ninja