diff --git a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
index a706129..bed72bc 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
@@ -318,6 +318,7 @@
     return directories;
   }
 
+  @Nullable
   public PathPackageLocator getPackageLocator() {
     return packageLocator;
   }