diff --git a/cluster/addons/cluster-monitoring/google/heapster-controller.yaml b/cluster/addons/cluster-monitoring/google/heapster-controller.yaml
index c021beb470b..7d56978c3c7 100644
--- a/cluster/addons/cluster-monitoring/google/heapster-controller.yaml
+++ b/cluster/addons/cluster-monitoring/google/heapster-controller.yaml
@@ -1,6 +1,7 @@
 {% set heapster_memory = "300Mi" -%}
-{% if pillar['num_nodes'] is defined and pillar['num_nodes'] is not None -%}
-  {% set heapster_memory = (200 + pillar['num_nodes'] * 12)|string + "Mi" -%}
+{% set num_nodes = pillar.get('num_nodes', -1) %}
+{% if num_nodes >= 0 %}
+  {% set heapster_memory = (200 + num_nodes * 12)|string + "Mi" -%}
 {% endif -%}
 
 apiVersion: v1
diff --git a/cluster/addons/cluster-monitoring/googleinfluxdb/heapster-controller-combined.yaml b/cluster/addons/cluster-monitoring/googleinfluxdb/heapster-controller-combined.yaml
index 9b9a15900b9..a073b05f52c 100644
--- a/cluster/addons/cluster-monitoring/googleinfluxdb/heapster-controller-combined.yaml
+++ b/cluster/addons/cluster-monitoring/googleinfluxdb/heapster-controller-combined.yaml
@@ -1,6 +1,7 @@
 {% set heapster_memory = "300Mi" -%}
-{% if pillar['num_nodes'] is defined and pillar['num_nodes'] is not None -%}
-  {% set heapster_memory = (200 + pillar['num_nodes'] * 12)|string + "Mi" -%}
+{% set num_nodes = pillar.get('num_nodes', -1) %}
+{% if num_nodes >= 0 %}
+  {% set heapster_memory = (200 + num_nodes * 12)|string + "Mi" -%}
 {% endif -%}
 
 apiVersion: v1
diff --git a/cluster/addons/cluster-monitoring/influxdb/heapster-controller.yaml b/cluster/addons/cluster-monitoring/influxdb/heapster-controller.yaml
index 63335ebed7f..5d2d06daa28 100644
--- a/cluster/addons/cluster-monitoring/influxdb/heapster-controller.yaml
+++ b/cluster/addons/cluster-monitoring/influxdb/heapster-controller.yaml
@@ -1,6 +1,7 @@
 {% set heapster_memory = "300Mi" -%}
-{% if pillar['num_nodes'] is defined and pillar['num_nodes'] is not None -%}
-  {% set heapster_memory = (200 + pillar['num_nodes'] * 12)|string + "Mi" -%}
+{% set num_nodes = pillar.get('num_nodes', -1) %}
+{% if num_nodes >= 0 %}
+  {% set heapster_memory = (200 + num_nodes * 12)|string + "Mi" -%}
 {% endif -%}
 
 apiVersion: v1
diff --git a/cluster/addons/cluster-monitoring/standalone/heapster-controller.yaml b/cluster/addons/cluster-monitoring/standalone/heapster-controller.yaml
index cf88dfbdbb0..3eee8d107c1 100644
--- a/cluster/addons/cluster-monitoring/standalone/heapster-controller.yaml
+++ b/cluster/addons/cluster-monitoring/standalone/heapster-controller.yaml
@@ -1,6 +1,7 @@
 {% set heapster_memory = "300Mi" -%}
-{% if pillar['num_nodes'] is defined and pillar['num_nodes'] is not None -%}
-  {% set heapster_memory = (200 + pillar['num_nodes'] * 12)|string + "Mi" -%}
+{% set num_nodes = pillar.get('num_nodes', -1) %}
+{% if num_nodes >= 0 %}
+  {% set heapster_memory = (200 + num_nodes * 12)|string + "Mi" -%}
 {% endif -%}
 
 apiVersion: v1