diff --git a/impl/google/services/mounttable/jni.go b/impl/google/services/mounttable/jni.go
index 217d96b..1cbec41 100644
--- a/impl/google/services/mounttable/jni.go
+++ b/impl/google/services/mounttable/jni.go
@@ -95,7 +95,7 @@
 		return nil
 
 	}
-	permsFile, err := ioutil.TempFile(os.TempDir(), "jni_permissions")
+	permsFile, err := ioutil.TempFile(rootDir, "jni_permissions")
 	if err != nil {
 		jutil.JThrowV(env, fmt.Errorf("Couldn't create permissions file: %v", err))
 		return nil