diff --git a/examples/build.gradle b/examples/build.gradle
index 918bf70f..5c1b1a0d 100644
--- a/examples/build.gradle
+++ b/examples/build.gradle
@@ -6,7 +6,7 @@ eclipse.project.name = 'bitcoinj-examples'
 dependencies {
     implementation project(':core')
     implementation 'com.google.guava:guava:27.0.1-android'
-    implementation 'net.sf.jopt-simple:jopt-simple:4.3'
+    implementation 'net.sf.jopt-simple:jopt-simple:5.0.4'
     implementation 'org.slf4j:slf4j-jdk14:1.7.25'
     implementation 'org.fusesource.leveldbjni:leveldbjni-all:1.8'
 }
diff --git a/examples/src/main/java/org/bitcoinj/examples/ExamplePaymentChannelClient.java b/examples/src/main/java/org/bitcoinj/examples/ExamplePaymentChannelClient.java
index 9ff00a87..e8db8f7e 100644
--- a/examples/src/main/java/org/bitcoinj/examples/ExamplePaymentChannelClient.java
+++ b/examples/src/main/java/org/bitcoinj/examples/ExamplePaymentChannelClient.java
@@ -89,7 +89,7 @@ public class ExamplePaymentChannelClient {
             }
         }
         NetworkParameters params = net.value(opts).get();
-        new ExamplePaymentChannelClient().run(opts.nonOptionArguments().get(0), clientChannelProperties, params);
+        new ExamplePaymentChannelClient().run((String) opts.nonOptionArguments().get(0), clientChannelProperties, params);
     }
 
     public ExamplePaymentChannelClient() {
diff --git a/examples/src/main/java/org/bitcoinj/examples/FetchBlock.java b/examples/src/main/java/org/bitcoinj/examples/FetchBlock.java
index acadd12c..5c5510b0 100644
--- a/examples/src/main/java/org/bitcoinj/examples/FetchBlock.java
+++ b/examples/src/main/java/org/bitcoinj/examples/FetchBlock.java
@@ -43,7 +43,7 @@ public class FetchBlock {
         // Parse command line arguments
         OptionParser parser = new OptionParser();
         OptionSet opts = null;
-        List<String> nonOpts = null;
+        List<byte[]> nonOpts = null;
         try {
             parser.accepts("localhost", "Connect to the localhost node");
             parser.accepts("help", "Displays program options");
@@ -53,7 +53,7 @@ public class FetchBlock {
                 parser.printHelpOn(System.out);
                 return;
             }
-            nonOpts = opts.nonOptionArguments();
+            nonOpts = (List<byte[]>) opts.nonOptionArguments();
             if (nonOpts.size() != 1) {
                 throw new IllegalArgumentException("Incorrect number of block hash, please provide only one block hash.");
             }
diff --git a/tools/build.gradle b/tools/build.gradle
index 4fadb7c1..9a78bfde 100644
--- a/tools/build.gradle
+++ b/tools/build.gradle
@@ -6,7 +6,7 @@ eclipse.project.name = 'bitcoinj-tools'
 dependencies {
     implementation project(':core')
     implementation 'com.google.guava:guava:27.0.1-android'
-    implementation 'net.sf.jopt-simple:jopt-simple:4.3'
+    implementation 'net.sf.jopt-simple:jopt-simple:5.0.4'
     implementation 'org.slf4j:slf4j-jdk14:1.7.25'
 }
 
diff --git a/tools/src/main/java/org/bitcoinj/tools/WalletTool.java b/tools/src/main/java/org/bitcoinj/tools/WalletTool.java
index 1fcb319a..0007c995 100644
--- a/tools/src/main/java/org/bitcoinj/tools/WalletTool.java
+++ b/tools/src/main/java/org/bitcoinj/tools/WalletTool.java
@@ -277,7 +277,7 @@ public class WalletTool {
 
         ActionEnum action;
         try {
-            String actionStr = options.nonOptionArguments().get(0);
+            String actionStr = (String) options.nonOptionArguments().get(0);
             actionStr = actionStr.toUpperCase().replace("-", "_");
             action = ActionEnum.valueOf(actionStr);
         } catch (IllegalArgumentException e) {