diff --git a/java/androidmk.go b/java/androidmk.go
index 0d4edfe..0700b58 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -454,6 +454,14 @@
 					fmt.Fprintln(w, dstubs.Name()+"-check-last-released-api:",
 						dstubs.checkLastReleasedApiTimestamp.String())
 				}
+				if dstubs.checkNullabilityWarningsTimestamp != nil {
+					fmt.Fprintln(w, ".PHONY:", dstubs.Name()+"-check-nullability-warnings")
+					fmt.Fprintln(w, dstubs.Name()+"-check-nullability-warnings:",
+						dstubs.checkNullabilityWarningsTimestamp.String())
+
+					fmt.Fprintln(w, ".PHONY:", "droidcore")
+					fmt.Fprintln(w, "droidcore: ", dstubs.Name()+"-check-nullability-warnings")
+				}
 				apiFilePrefix := "INTERNAL_PLATFORM_"
 				if String(dstubs.properties.Api_tag_name) != "" {
 					apiFilePrefix += String(dstubs.properties.Api_tag_name) + "_"