diff --git a/manifests/init.pp b/manifests/init.pp
index 94a1c9f..0b08c63 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -75,7 +75,9 @@ class logstash {
     mode   => '0644',
   }
 
-  package { 'openjdk-7-jre-headless':
-    ensure => present,
+  if ! defined(Package['openjdk-7-jre-headless']) {
+    package { 'openjdk-7-jre-headless':
+      ensure => present,
+    }
   }
 }
diff --git a/manifests/watchdog.pp b/manifests/watchdog.pp
index 8199192..48aa575 100644
--- a/manifests/watchdog.pp
+++ b/manifests/watchdog.pp
@@ -23,8 +23,10 @@ class logstash::watchdog (
   package { 'jq':
     ensure => present,
   }
-  package { 'curl':
-    ensure => present,
+  if ! defined(Package['curl']) {
+    package { 'curl':
+      ensure => present,
+    }
   }
 
   file { '/usr/local/bin/logstash-watchdog':