diff --git a/build.gradle.kts b/build.gradle.kts
index e8fff64..8dfc1cc 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -72,7 +72,7 @@ sonar {
 val versions = mapOf(
     "QUARKUS_SCALA3"        to "1.0.0",
     "SCALA3"                to "3.5.1",
-    "SCALA_LIBRARY"         to "2.13.18",
+    "SCALA_LIBRARY"         to "2.13.16",
     "SCALATEST"             to "3.2.19",
     "SCALATEST_JUNIT"       to "0.1.11",
     "SCOVERAGE"             to "2.1.1",
diff --git a/modules/core/build.gradle.kts b/modules/core/build.gradle.kts
index a02a07c..d572500 100644
--- a/modules/core/build.gradle.kts
+++ b/modules/core/build.gradle.kts
@@ -74,6 +74,7 @@ dependencies {
     testImplementation("org.scalatest:scalatest_3:${versions["SCALATEST"]!!}")
     testImplementation("co.helmethair:scalatest-junit-runner:${versions["SCALATEST_JUNIT"]!!}")
     testImplementation("io.quarkus:quarkus-junit5")
+    testImplementation("io.quarkus:quarkus-junit5-mockito")
     testImplementation("io.rest-assured:rest-assured")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
diff --git a/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala b/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
index bf165cc..1ee458e 100644
--- a/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
+++ b/modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala
@@ -1,11 +1,19 @@
 package de.nowchess.chess.resource
 
 import de.nowchess.api.dto.*
+import de.nowchess.api.game.GameContext
+import de.nowchess.chess.client.IoServiceClient
 import de.nowchess.chess.exception.BadRequestException
+import de.nowchess.io.fen.FenExporter
+import de.nowchess.io.pgn.PgnParser
+import io.quarkus.test.InjectMock
 import io.quarkus.test.junit.QuarkusTest
 import jakarta.inject.Inject
-import org.junit.jupiter.api.{DisplayName, Test}
+import org.eclipse.microprofile.rest.client.inject.RestClient
+import org.junit.jupiter.api.{BeforeEach, DisplayName, Test}
 import org.junit.jupiter.api.Assertions.*
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mockito.when
 
 import scala.compiletime.uninitialized
 
@@ -17,6 +25,19 @@ class GameResourceIntegrationTest:
   @Inject
   var resource: GameResource = uninitialized
 
+  @InjectMock
+  @RestClient
+  var ioClient: IoServiceClient = uninitialized
+
+  @BeforeEach
+  def setupMocks(): Unit =
+    when(ioClient.importFen(any())).thenReturn(GameContext.initial)
+    when(ioClient.importPgn(any())).thenReturn(
+      PgnParser.importGameContext("1. e4 c5").toOption.get,
+    )
+    when(ioClient.exportFen(any())).thenReturn(FenExporter.exportGameContext(GameContext.initial))
+    when(ioClient.exportPgn(any())).thenReturn("1. e4 c5")
+
   @Test
   @DisplayName("createGame returns 201")
   def testCreateGame(): Unit =
diff --git a/modules/io/build.gradle.kts b/modules/io/build.gradle.kts
index 7a6751d..61ea69d 100644
--- a/modules/io/build.gradle.kts
+++ b/modules/io/build.gradle.kts
@@ -77,6 +77,18 @@ dependencies {
     testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
 }
 
+
+configurations.matching { !it.name.startsWith("scoverage") }.configureEach {
+    resolutionStrategy.force("org.scala-lang:scala-library:${versions["SCALA_LIBRARY"]!!}")
+}
+configurations.scoverage {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.scoverage" && requested.name.startsWith("scalac-scoverage-plugin_")) {
+            useTarget("${requested.group}:scalac-scoverage-plugin_2.13.16:2.3.0")
+        }
+    }
+}
+
 tasks.withType<JavaCompile> {
     options.encoding = "UTF-8"
     options.compilerArgs.add("-parameters")