diff --git a/app/build.gradle.sonar.kts b/app/build.gradle.sonar.kts
index 48a4fd4..a4c9d9d 100644
--- a/app/build.gradle.sonar.kts
+++ b/app/build.gradle.sonar.kts
@@ -22,6 +22,7 @@ repositories {
 dependencies {
     // Use JUnit Jupiter for testing.
     testImplementation(libs.junit.jupiter)
+    testImplementation("org.assertj:assertj-core:3.25.3")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")