diff --git a/pom.xml b/pom.xml
index 3f7fa66..76bd3fb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -30,7 +30,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
 
diff --git a/simple_02/pom.xml b/simple_02/pom.xml
index c645b09..cd0e85b 100644
--- a/simple_02/pom.xml
+++ b/simple_02/pom.xml
@@ -25,7 +25,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/simple_03/pom.xml b/simple_03/pom.xml
index b4120f6..5b88367 100644
--- a/simple_03/pom.xml
+++ b/simple_03/pom.xml
@@ -25,7 +25,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/simple_04/pom.xml b/simple_04/pom.xml
index b3a832d..03a4abc 100644
--- a/simple_04/pom.xml
+++ b/simple_04/pom.xml
@@ -25,7 +25,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/simple_1/pom.xml b/simple_1/pom.xml
index bf05b1e..c631522 100644
--- a/simple_1/pom.xml
+++ b/simple_1/pom.xml
@@ -25,7 +25,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>