diff --git a/pom.xml b/pom.xml
index f34050fe5..5d89ebcc8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -116,7 +116,7 @@
         <dependency>
             <groupId>commons-cli</groupId>
             <artifactId>commons-cli</artifactId>
-            <version>1.4</version>
+            <version>1.9.0</version>
         </dependency>
         <dependency>
             <groupId>org.scala-lang</groupId>
diff --git a/src/main/java/io/confluent/examples/streams/microservices/AddInventory.java b/src/main/java/io/confluent/examples/streams/microservices/AddInventory.java
index e07bc8b1e..0922e4a93 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/AddInventory.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/AddInventory.java
@@ -77,7 +77,7 @@ public static void main(final String[] args) throws Exception {
 
         final String bootstrapServers = cl.getOptionValue("b", DEFAULT_BOOTSTRAP_SERVERS);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/EmailService.java b/src/main/java/io/confluent/examples/streams/microservices/EmailService.java
index 7ba1dfbce..6def03ced 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/EmailService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/EmailService.java
@@ -152,7 +152,7 @@ public static void main(final String[] args) throws Exception {
     }
     final EmailService service = new EmailService(new LoggingEmailer());
 
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/FraudService.java b/src/main/java/io/confluent/examples/streams/microservices/FraudService.java
index ec517d4e7..ef0a8b169 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/FraudService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/FraudService.java
@@ -166,7 +166,7 @@ public static void main(final String[] args) throws Exception {
       return;
     }
     final FraudService service = new FraudService();
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/InventoryService.java b/src/main/java/io/confluent/examples/streams/microservices/InventoryService.java
index 56bf9af02..6b6244b69 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/InventoryService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/InventoryService.java
@@ -200,7 +200,7 @@ public static void main(final String[] args) throws Exception {
       return;
     }
 
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/OrderDetailsService.java b/src/main/java/io/confluent/examples/streams/microservices/OrderDetailsService.java
index 00a3b6f3e..3bfe35b37 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/OrderDetailsService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/OrderDetailsService.java
@@ -217,7 +217,7 @@ public static void main(final String[] args) throws Exception {
       formatter.printHelp("Order Details Service", opts);
       return;
     }
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/OrdersService.java b/src/main/java/io/confluent/examples/streams/microservices/OrdersService.java
index e65d71e52..d99234dcd 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/OrdersService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/OrdersService.java
@@ -451,7 +451,7 @@ public static void main(final String[] args) throws Exception {
     final int restPort = Integer.parseInt(cl.getOptionValue("port", "5432"));
     final String stateDir = cl.getOptionValue("state-dir", "/tmp/kafka-streams");
 
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/PostOrdersAndPayments.java b/src/main/java/io/confluent/examples/streams/microservices/PostOrdersAndPayments.java
index eb76d479c..42803bc2c 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/PostOrdersAndPayments.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/PostOrdersAndPayments.java
@@ -94,7 +94,7 @@ public static void main(final String[] args) throws Exception {
         final String orderServiceUrl = cl.getOptionValue("order-service-url", "http://localhost:5432");
         final int startingOrderId = Integer.parseInt(cl.getOptionValue("order-id", "1"));
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/ValidationsAggregatorService.java b/src/main/java/io/confluent/examples/streams/microservices/ValidationsAggregatorService.java
index a0660bbcd..1fbfdc9ec 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/ValidationsAggregatorService.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/ValidationsAggregatorService.java
@@ -180,7 +180,7 @@ public static void main(final String[] args) throws Exception {
       formatter.printHelp("Validator Aggregator Service", opts);
       return;
     }
-    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+    final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
               try {
                 return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeCustomers.java b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeCustomers.java
index 197c950d9..bd5bb131a 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeCustomers.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeCustomers.java
@@ -39,7 +39,7 @@ public static void main(final String[] args) throws Exception {
         final String bootstrapServers = cl.getOptionValue("b", DEFAULT_BOOTSTRAP_SERVERS);
         final String schemaRegistryUrl = cl.getOptionValue("schema-registry", DEFAULT_SCHEMA_REGISTRY_URL);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeOrders.java b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeOrders.java
index 065850407..4ef73db24 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeOrders.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumeOrders.java
@@ -39,7 +39,7 @@ public static void main(final String[] args) throws Exception {
         final String bootstrapServers = cl.getOptionValue("b", DEFAULT_BOOTSTRAP_SERVERS);
         final String schemaRegistryUrl = cl.getOptionValue("schema-registry", DEFAULT_SCHEMA_REGISTRY_URL);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumePayments.java b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumePayments.java
index 3700b582a..f082fe18d 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ConsumePayments.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ConsumePayments.java
@@ -38,7 +38,7 @@ public static void main(final String[] args) throws Exception {
         final String bootstrapServers = cl.getOptionValue("b", DEFAULT_BOOTSTRAP_SERVERS);
         final String schemaRegistryUrl = cl.getOptionValue("schema-registry", DEFAULT_SCHEMA_REGISTRY_URL);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ProduceCustomers.java b/src/main/java/io/confluent/examples/streams/microservices/util/ProduceCustomers.java
index da2d6a95e..a9a702a0f 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ProduceCustomers.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ProduceCustomers.java
@@ -45,7 +45,7 @@ public static void main(final String[] args) throws Exception {
             Collections.singletonMap(AbstractKafkaSchemaSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, schemaRegistryUrl),
             isKeySerde);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
             .map(path -> {
                 try {
                     return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ProduceOrders.java b/src/main/java/io/confluent/examples/streams/microservices/util/ProduceOrders.java
index a1c9e99d2..05b31e4da 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ProduceOrders.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ProduceOrders.java
@@ -39,7 +39,7 @@ public static void main(final String[] args) throws Exception {
 
         final CommandLine cl = new DefaultParser().parse(opts, args);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);
diff --git a/src/main/java/io/confluent/examples/streams/microservices/util/ProducePayments.java b/src/main/java/io/confluent/examples/streams/microservices/util/ProducePayments.java
index d1b1ec78b..4760e748a 100644
--- a/src/main/java/io/confluent/examples/streams/microservices/util/ProducePayments.java
+++ b/src/main/java/io/confluent/examples/streams/microservices/util/ProducePayments.java
@@ -37,7 +37,7 @@ public static void main(final String[] args) throws Exception {
 
         final CommandLine cl = new DefaultParser().parse(opts, args);
 
-        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", null))
+        final Properties defaultConfig = Optional.ofNullable(cl.getOptionValue("config-file", (String) null))
                 .map(path -> {
                     try {
                         return buildPropertiesFromConfigFile(path);