diff --git a/dual-master/Makefile b/dual-master/Makefile
index 133dabe..16ded99 100644
--- a/dual-master/Makefile
+++ b/dual-master/Makefile
@@ -63,6 +63,12 @@
 ifdef VPC_CIDR
 		$(eval CLUSTER_OPTIONAL_PARAMS := $(CLUSTER_OPTIONAL_PARAMS) ParameterKey=VPCCIDR,ParameterValue=$(VPC_CIDR))
 endif
+ifdef HA_PROXY_MAX_COUNT
+		$(eval CLUSTER_OPTIONAL_PARAMS := $(CLUSTER_OPTIONAL_PARAMS) ParameterKey=HAProxyMaxCount,ParameterValue=$(HA_PROXY_MAX_COUNT))
+endif
+ifdef HA_PROXY_DESIRED_COUNT
+		$(eval CLUSTER_OPTIONAL_PARAMS := $(CLUSTER_OPTIONAL_PARAMS) ParameterKey=HAProxyDesiredCount,ParameterValue=$(HA_PROXY_DESIRED_COUNT))
+endif
 
 	$(AWS_FC_COMMAND) create-stack \
 		--stack-name $(CLUSTER_STACK_NAME) \
@@ -237,6 +243,9 @@
 ifdef LOAD_BALANCER_SCHEME
 		$(eval SERVICE_OPTIONAL_PARAMS := $(SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
 endif
+ifdef HA_PROXY_DESIRED_COUNT
+		$(eval SERVICE_OPTIONAL_PARAMS := $(SERVICE_OPTIONAL_PARAMS) ParameterKey=DesiredCount,ParameterValue=$(HA_PROXY_DESIRED_COUNT))
+endif
 
 	$(AWS_FC_COMMAND) create-stack \
 		--stack-name $(LOAD_BALANCER_STACK_NAME) \
diff --git a/dual-master/README.md b/dual-master/README.md
index fbdb39e..6836d0f 100644
--- a/dual-master/README.md
+++ b/dual-master/README.md
@@ -108,6 +108,17 @@
 * `GERRIT_MASTER2_INSTANCE_ID`: Optional. Identifier for the Gerrit master2 instance.
 "gerrit-dual-master-MASTER2" by default.
 
+* `HA_PROXY_DESIRED_COUNT`: Optional. Desired number of haproxy services.
+"2" by default. Minimum: "2".
+
+*Note* ha-proxies are running on ec2 instances with a ratio of 1 to 1: each
+ec2 node hosts one and only one ha-proxy. By increasing the number of desired
+ha-proxies then, the size of the autoscaling group hosting them also increases
+accordingly.
+
+* `HA_PROXY_MAX_COUNT`: Optional. Maximum number of EC2 instances in the haproxy autoscaling group.
+"2" by default. Minimum: "2".
+
 #### REPLICATION SERVICE
 
 * `REPLICATION_SERVICE_ENABLED`: Optional. Whether to expose a replication endpoint.
diff --git a/dual-master/cf-cluster.yml b/dual-master/cf-cluster.yml
index e41b185..ee620a4 100644
--- a/dual-master/cf-cluster.yml
+++ b/dual-master/cf-cluster.yml
@@ -65,6 +65,16 @@
     Description:  The fs throughput, measured in MiB/s. Valid values are 1-1024.
     Type: Number
     Default: 256
+  HAProxyMaxCount:
+    Description: The maximum number of EC2 instances in the haproxy autoscaling group
+    Type: Number
+    Default: 2
+  HAProxyDesiredCount:
+    Description: The desired number of haproxy instances
+    ConstraintDescription: number of haproxy must be at least 2
+    Type: Number
+    MinValue: 2
+    Default: 2
 
 Conditions:
   isProvisionedThroughput: !Equals [!Ref FileSystemThroughputMode, "provisioned"]
@@ -137,9 +147,9 @@
       VPCZoneIdentifier:
         - !GetAtt ECSTaskNetworkStack.Outputs.PublicSubnetOneRef
       LaunchConfigurationName: !Ref 'HAProxyLaunchConfiguration'
-      MinSize: '1'
-      MaxSize: '1'
-      DesiredCapacity: '1'
+      MinSize: '2'
+      MaxSize: !Ref HAProxyMaxCount
+      DesiredCapacity: !Ref HAProxyDesiredCount
     CreationPolicy:
       ResourceSignal:
         Timeout: PT15M
diff --git a/dual-master/cf-service-lb.yml b/dual-master/cf-service-lb.yml
index 27f41fa..d2795ff 100644
--- a/dual-master/cf-service-lb.yml
+++ b/dual-master/cf-service-lb.yml
@@ -29,7 +29,9 @@
   DesiredCount:
         Description: How many instances of this task should we run across our cluster?
         Type: Number
-        Default: 1
+        MinValue: 2
+        Default: 2
+        ConstraintDescription: number of haproxy must be at least 2
   HTTPGerritPort:
         Description: Gerrit HTTP port
         Type: Number
diff --git a/dual-master/setup.env.template b/dual-master/setup.env.template
index 99bbf84..d986e66 100644
--- a/dual-master/setup.env.template
+++ b/dual-master/setup.env.template
@@ -56,3 +56,6 @@
 METRICS_CLOUDWATCH_JVM_ENABLED:=true
 METRICS_CLOUDWATCH_DRY_RUN:=false
 METRICS_CLOUDWATCH_EXCLUDE_METRICS_LIST:=foo.*,bar.*
+
+HA_PROXY_MAX_COUNT:=2
+HA_PROXY_DESIRED_COUNT:=2