diff --git a/build.gradle b/build.gradle
index 4773142..c30a4a0 100644
--- a/build.gradle
+++ b/build.gradle
@@ -46,8 +46,12 @@ sourceSets {
 }
 
 dependencies {
-    // All existing JARs from lib/
-    implementation fileTree(dir: 'lib', include: ['*.jar'])
+    // All existing JARs from lib/. Test framework jars are excluded so Gradle uses the
+    // managed testImplementation versions below; they stay in lib/ for Eclipse to compile against.
+    implementation fileTree(dir: 'lib', include: ['*.jar'],
+        exclude: ['junit-*.jar', 'jupiter-*.jar', 'mockito-*.jar',
+                  'opentest4j-*.jar', 'apiguardian-*.jar',
+                  'byte-buddy-*.jar', 'objenesis-*.jar'])
 
     // Test dependencies
     testImplementation 'org.junit.jupiter:junit-jupiter:5.11.4'
diff --git a/lib/junit-jupiter-api-5.11.4.jar b/lib/junit-jupiter-api-5.11.4.jar
new file mode 100644
index 0000000..035c0a4
Binary files /dev/null and b/lib/junit-jupiter-api-5.11.4.jar differ
diff --git a/lib/junit-jupiter-api-6.1.1.jar b/lib/junit-jupiter-api-6.1.1.jar
deleted file mode 100644
index 6701039..0000000
Binary files a/lib/junit-jupiter-api-6.1.1.jar and /dev/null differ
diff --git a/lib/junit-jupiter-params-5.11.4.jar b/lib/junit-jupiter-params-5.11.4.jar
new file mode 100644
index 0000000..5f7a693
Binary files /dev/null and b/lib/junit-jupiter-params-5.11.4.jar differ
diff --git a/lib/junit-jupiter-params-6.1.1.jar b/lib/junit-jupiter-params-6.1.1.jar
deleted file mode 100644
index af090d4..0000000
Binary files a/lib/junit-jupiter-params-6.1.1.jar and /dev/null differ
diff --git a/lib/mockito-core-5.23.0.jar b/lib/mockito-core-5.14.2.jar
similarity index 65%
rename from lib/mockito-core-5.23.0.jar
rename to lib/mockito-core-5.14.2.jar
index 48c3331..f405025 100644
Binary files a/lib/mockito-core-5.23.0.jar and b/lib/mockito-core-5.14.2.jar differ