diff --git a/test/org/rascalmpl/test/rpc/IValueOverJsonTests.java b/test/org/rascalmpl/test/rpc/IValueOverJsonTests.java
index 115522aa92a..417dadbe87d 100644
--- a/test/org/rascalmpl/test/rpc/IValueOverJsonTests.java
+++ b/test/org/rascalmpl/test/rpc/IValueOverJsonTests.java
@@ -13,6 +13,7 @@
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -72,6 +73,7 @@ public class IValueOverJsonTests {
     private JsonRpcTestInterface testServer;
     private final PipedInputStream is0, is1;
     private final PipedOutputStream os0, os1;
+    private final ExecutorService exec = Executors.newCachedThreadPool();
 
     @Parameters(name="{0}")
     public static Iterable<Object[]> modesAndConfig() {
@@ -92,7 +94,7 @@ public IValueOverJsonTests(ComplexTypeMode complexTypeMode, Consumer<GsonBuilder
             os0 = new PipedOutputStream();
             is1 = new PipedInputStream(os0);
             os1 = new PipedOutputStream(is0);
-            new TestThread(is0, os0, gsonConfig).start();
+            new TestThread(is0, os0, gsonConfig, exec).start();
             new TestClient(is1, os1, gsonConfig);
         } catch (IOException e) {
             throw new RuntimeException(e);
@@ -101,6 +103,7 @@ public IValueOverJsonTests(ComplexTypeMode complexTypeMode, Consumer<GsonBuilder
 
     @After
     public void teardown() throws IOException {
+        exec.shutdown();
         if (is0 != null) {
             is0.close();
         }
@@ -118,12 +121,16 @@ public void teardown() throws IOException {
     class TestClient {
         public TestClient(InputStream is, OutputStream os, Consumer<GsonBuilder> gsonConfig) {
             Launcher<JsonRpcTestInterface> clientLauncher = new Launcher.Builder<JsonRpcTestInterface>()
-                .setRemoteInterface(JsonRpcTestInterface.class)
                 .setLocalService(this)
+                .setRemoteInterface(JsonRpcTestInterface.class)
                 .setInput(is)
                 .setOutput(os)
                 .configureGson(gsonConfig)
-                .setExecutorService(Executors.newCachedThreadPool())
+                .setExceptionHandler(e -> {
+                    System.err.println(e);
+                    return new ResponseError(ResponseErrorCode.InternalError, e.getMessage(), e);
+                })
+                .setExecutorService(exec)
                 .create();
 
             clientLauncher.startListening();
@@ -135,11 +142,13 @@ static class TestThread extends Thread {
         private final InputStream is;
         private final OutputStream os;
         private final Consumer<GsonBuilder> gsonConfig;
+        private final ExecutorService exec;
         
-        public TestThread(InputStream is, OutputStream os, Consumer<GsonBuilder> gsonConfig) {
+        public TestThread(InputStream is, OutputStream os, Consumer<GsonBuilder> gsonConfig, ExecutorService exec) {
             this.is = is;
             this.os = os;
             this.gsonConfig = gsonConfig;
+            this.exec = exec;
             this.setDaemon(true);
         }
 
@@ -155,13 +164,14 @@ public void run() {
                     System.err.println(e);
                     return new ResponseError(ResponseErrorCode.InternalError, e.getMessage(), e);
                 })
+                .setExecutorService(exec)
                 .create();
 
             serverLauncher.startListening();
         }
     }
 
-    private static Set<ComplexTypeMode> asJsonObjectOrNotSupported = new HashSet<>(Arrays.asList(ComplexTypeMode.ENCODE_AS_JSON_OBJECT, ComplexTypeMode.NOT_SUPPORTED));
+    private static final Set<ComplexTypeMode> asJsonObjectOrNotSupported = new HashSet<>(Arrays.asList(ComplexTypeMode.ENCODE_AS_JSON_OBJECT, ComplexTypeMode.NOT_SUPPORTED));
 
     private <T extends IValue> void runTestForPrimitiveType(String type, Supplier<T> supplier, Function<T, CompletableFuture<T>> function) {
         expectSuccessful(type, supplier, function);