diff --git a/java/droiddoc.go b/java/droiddoc.go
index 4c3e112..68cfe9f 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -1470,7 +1470,7 @@
 		FlagWithInput("@", srcJarList).
 		FlagWithOutput("--strict-input-files:warn ", android.PathForModuleOut(ctx, ctx.ModuleName()+"-"+"violations.txt"))
 
-	if implicitsRsp.String() != "" {
+	if implicitsRsp != nil {
 		cmd.FlagWithArg("--strict-input-files-exempt ", "@"+implicitsRsp.String())
 	}