diff --git a/pom.xml b/pom.xml
index 25da0fe..473fb58 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,22 +4,50 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>io.diffblue.corebanking</groupId>
   <artifactId>CoreBanking</artifactId>
-  <version>1.0.0</version>
+  <version>1.0.1-JUnit5</version>
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <maven.compiler.source>1.8</maven.compiler.source>
     <maven.compiler.target>1.8</maven.compiler.target>
+    <jacoco.version>0.8.5</jacoco.version>
   </properties>
   <dependencies>
+    <!-- Only for JCover -->
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.13.2</version>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <version>4.7.0</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <version>5.5.2</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.jacoco</groupId>
+      <artifactId>org.jacoco.agent</artifactId>
+      <version>0.8.2</version>
+      <scope>test</scope>
+      <classifier>runtime</classifier>
+    </dependency>
   </dependencies>
   <build>
     <plugins>
+      <!-- DIFFBLUE -->
+      <plugin>
+        <groupId>org.pitest</groupId>
+        <artifactId>pitest-maven</artifactId>
+        <version>1.5.2</version>
+        <dependencies>
+          <dependency>
+            <groupId>org.pitest</groupId>
+            <artifactId>pitest-junit5-plugin</artifactId>
+            <version>0.12</version>
+          </dependency>
+        </dependencies>
+      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-assembly-plugin</artifactId>
@@ -52,7 +80,33 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-surefire-plugin</artifactId>
-        <version>3.0.0</version>
+        <version>3.0.0-M3</version>
+        <dependencies>
+          <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-surefire-provider</artifactId>
+            <version>1.2.0</version>
+          </dependency>
+        </dependencies>
+      </plugin>
+      <plugin>
+        <groupId>org.jacoco</groupId>
+        <artifactId>jacoco-maven-plugin</artifactId>
+        <version>${jacoco.version}</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>prepare-agent</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>report</id>
+            <phase>prepare-package</phase>
+            <goals>
+              <goal>report</goal>
+            </goals>
+          </execution>
+        </executions>
       </plugin>
     </plugins>
   </build>
diff --git a/src/main/java/io/diffblue/corebanking/account/Account.java b/src/main/java/io/diffblue/corebanking/account/Account.java
index 9afe07d..3ea5a83 100644
--- a/src/main/java/io/diffblue/corebanking/account/Account.java
+++ b/src/main/java/io/diffblue/corebanking/account/Account.java
@@ -91,7 +91,7 @@ public void takeFromBalance(final long amount) throws AccountException {
     if (getAccountState() != AccountState.OPEN) {
       throw new AccountException("Cannot take from balance, account is closed.");
     }
-    if (currentBalance + amount < 0) {
+    if (currentBalance - amount < 0) {
       throw new AccountException(
           "Trying to take "
               + amount
@@ -208,7 +208,7 @@ public class AccountStatement {
     private final List<Transaction> transactions;
 
     /** Constructor. */
-    private AccountStatement() {
+    public AccountStatement() {
       transactions = new ArrayList<Transaction>();
     }