diff --git a/gradle.properties b/gradle.properties
index 21e67c015a..588a601bc1 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -69,7 +69,3 @@ shadowPluginVersion=4.0.4
 # https://issues.sonatype.org/browse/MVNCENTRAL-5276
 # https://issues.apache.org/jira/browse/INFRA-14923
 systemProp.org.gradle.internal.publish.checksums.insecure=true
-
-# Test properties
-# expected format for timeout: <number>[ns|μs|ms|s|m|h|d])
-junit5DefaultTimeout=30s
diff --git a/servicetalk-concurrent-api/build.gradle b/servicetalk-concurrent-api/build.gradle
index b9d855f6e8..0be096b020 100644
--- a/servicetalk-concurrent-api/build.gradle
+++ b/servicetalk-concurrent-api/build.gradle
@@ -16,14 +16,6 @@
 
 apply plugin: "io.servicetalk.servicetalk-gradle-plugin-internal-library"
 
-test {
-  useJUnitPlatform()
-  def junit5TimeoutParamName = "junit.jupiter.execution.timeout.default"
-  def junit5Timeout = System.getProperty(junit5TimeoutParamName, "$junit5DefaultTimeout")
-  systemProperty junit5TimeoutParamName, "$junit5Timeout"
-  systemProperty "junit.jupiter.extensions.autodetection.enabled", "true"
-}
-
 dependencies {
   api project(":servicetalk-concurrent")
 
diff --git a/servicetalk-gradle-plugin-internal/src/main/groovy/io/servicetalk/gradle/plugin/internal/ServiceTalkLibraryPlugin.groovy b/servicetalk-gradle-plugin-internal/src/main/groovy/io/servicetalk/gradle/plugin/internal/ServiceTalkLibraryPlugin.groovy
index 5e67f4ca36..fcb298a794 100644
--- a/servicetalk-gradle-plugin-internal/src/main/groovy/io/servicetalk/gradle/plugin/internal/ServiceTalkLibraryPlugin.groovy
+++ b/servicetalk-gradle-plugin-internal/src/main/groovy/io/servicetalk/gradle/plugin/internal/ServiceTalkLibraryPlugin.groovy
@@ -161,6 +161,14 @@ final class ServiceTalkLibraryPlugin extends ServiceTalkCorePlugin {
   private static void configureTests(Project project) {
     project.configure(project) {
       test {
+        useJUnitPlatform()
+        // expected format for timeout: <number>[ns|μs|ms|s|m|h|d])
+        def junit5DefaultTimeout = Boolean.valueOf(System.getenv("CI") ?: "false") ? "30s" : "10s"
+        def junit5TimeoutParamName = "junit.jupiter.execution.timeout.default"
+        def junit5Timeout = System.getProperty(junit5TimeoutParamName, "$junit5DefaultTimeout")
+        systemProperty junit5TimeoutParamName, "$junit5Timeout"
+        systemProperty "junit.jupiter.extensions.autodetection.enabled", "true"
+
         testLogging {
           events "passed", "skipped", "failed"
           showStandardStreams = true
@@ -169,6 +177,13 @@ final class ServiceTalkLibraryPlugin extends ServiceTalkCorePlugin {
         jvmArgs "-server", "-Xms2g", "-Xmx4g", "-dsa", "-da", "-ea:io.servicetalk...",
                 "-XX:+HeapDumpOnOutOfMemoryError"
       }
+
+      dependencies {
+        testRuntimeOnly("org.junit.vintage:junit-vintage-engine:$junit5Version") {
+          because 'allows JUnit 3 and JUnit 4 tests to run'
+        }
+      }
+
     }
   }