diff --git a/async-program-demo/Chapter5/pom.xml b/async-program-demo/Chapter5/pom.xml
index 1f38762..424db9a 100644
--- a/async-program-demo/Chapter5/pom.xml
+++ b/async-program-demo/Chapter5/pom.xml
@@ -48,7 +48,7 @@
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>3.8.1</version>
+			<version>4.13.1</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
diff --git a/async-program-demo/Chapter8/pom.xml b/async-program-demo/Chapter8/pom.xml
index 6ac77f4..173870e 100644
--- a/async-program-demo/Chapter8/pom.xml
+++ b/async-program-demo/Chapter8/pom.xml
@@ -26,7 +26,7 @@
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>3.8.1</version>
+			<version>4.13.1</version>
 			<scope>test</scope>
 		</dependency>
 		<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
diff --git a/async-program-demo/ChapterIV/pom.xml b/async-program-demo/ChapterIV/pom.xml
index c17c0fc..5e73f25 100644
--- a/async-program-demo/ChapterIV/pom.xml
+++ b/async-program-demo/ChapterIV/pom.xml
@@ -33,7 +33,7 @@
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>3.8.1</version>
+			<version>4.13.1</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
diff --git a/async-program-demo/First-Chapter/pom.xml b/async-program-demo/First-Chapter/pom.xml
index 716df24..c8e6496 100644
--- a/async-program-demo/First-Chapter/pom.xml
+++ b/async-program-demo/First-Chapter/pom.xml
@@ -19,7 +19,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>3.8.1</version>
+      <version>4.13.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
diff --git a/async-program-demo/Second-Chapter/pom.xml b/async-program-demo/Second-Chapter/pom.xml
index 9ad5810..6e3de5b 100644
--- a/async-program-demo/Second-Chapter/pom.xml
+++ b/async-program-demo/Second-Chapter/pom.xml
@@ -19,7 +19,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>3.8.1</version>
+      <version>4.13.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
diff --git a/async-program-demo/Third-Chapter/pom.xml b/async-program-demo/Third-Chapter/pom.xml
index 357829b..b58f69d 100644
--- a/async-program-demo/Third-Chapter/pom.xml
+++ b/async-program-demo/Third-Chapter/pom.xml
@@ -19,7 +19,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>3.8.1</version>
+      <version>4.13.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
diff --git a/async-program-demo/pom.xml b/async-program-demo/pom.xml
index 0fdfa20..a531c5e 100644
--- a/async-program-demo/pom.xml
+++ b/async-program-demo/pom.xml
@@ -18,7 +18,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>3.8.1</version>
+      <version>4.13.1</version>
       <scope>test</scope>
     </dependency>
   </dependencies>