diff --git a/spring-modulith-junit/src/main/java/org/springframework/modulith/junit/TestExecutionCondition.java b/spring-modulith-junit/src/main/java/org/springframework/modulith/junit/TestExecutionCondition.java
index 48a3d0087..e5b137aac 100644
--- a/spring-modulith-junit/src/main/java/org/springframework/modulith/junit/TestExecutionCondition.java
+++ b/spring-modulith-junit/src/main/java/org/springframework/modulith/junit/TestExecutionCondition.java
@@ -15,8 +15,8 @@
  */
 package org.springframework.modulith.junit;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Function;
 
 import org.jspecify.annotations.Nullable;
@@ -45,7 +45,7 @@ class TestExecutionCondition {
 	private static final Logger log = LoggerFactory.getLogger(TestExecutionCondition.class);
 	private static final AnnotatedClassFinder SPA_CLASS_FINDER = new AnnotatedClassFinder(SpringBootConfiguration.class);
 
-	private final Map<ApplicationModule, ApplicationModuleDependencies> dependencies = new HashMap<>();
+	private final Map<ApplicationModule, ApplicationModuleDependencies> dependencies = new ConcurrentHashMap<>();
 
 	ConditionEvaluationResult evaluate(ConditionContext context) {