diff --git a/master-slave/Makefile b/master-slave/Makefile
index 1b9fec8..8165414 100644
--- a/master-slave/Makefile
+++ b/master-slave/Makefile
@@ -43,7 +43,7 @@
 
 service-master: set-optional-params-metrics-cloudwatch
 ifdef LOAD_BALANCER_SCHEME
-		$(eval SERVICE_OPTIONAL_PARAMS := $(SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
+		$(eval MASTER_SERVICE_OPTIONAL_PARAMS := $(MASTER_SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
 endif
 
 	$(AWS_FC_COMMAND) create-stack \
@@ -73,12 +73,12 @@
 		ParameterKey=GerritCPU,ParameterValue=$(GERRIT_CPU) \
 		ParameterKey=GerritHeapLimit,ParameterValue=$(GERRIT_HEAP_LIMIT) \
 		ParameterKey=JgitCacheSize,ParameterValue=$(JGIT_CACHE_SIZE) \
-		$(SERVICE_OPTIONAL_PARAMS) \
+		$(MASTER_SERVICE_OPTIONAL_PARAMS) \
 		$(METRICS_CW_OPTIONAL_PARAMS)
 
 service-slave: set-optional-params-metrics-cloudwatch
 ifdef LOAD_BALANCER_SCHEME
-		$(eval SERVICE_OPTIONAL_PARAMS := $(SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
+		$(eval SLAVE_SERVICE_OPTIONAL_PARAMS := $(SLAVE_SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
 endif
 
 	$(AWS_FC_COMMAND) create-stack \
@@ -103,7 +103,7 @@
 		ParameterKey=GerritCPU,ParameterValue=$(GERRIT_CPU) \
 		ParameterKey=GerritHeapLimit,ParameterValue=$(GERRIT_HEAP_LIMIT) \
 		ParameterKey=JgitCacheSize,ParameterValue=$(JGIT_CACHE_SIZE) \
-		$(SERVICE_OPTIONAL_PARAMS) \
+		$(SLAVE_SERVICE_OPTIONAL_PARAMS) \
 		$(METRICS_CW_OPTIONAL_PARAMS)
 
 dns-routing: