diff --git a/beam/tools/src/main/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStream.java b/beam/tools/src/main/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStream.java
index 3df87ebdd..93d379ff3 100644
--- a/beam/tools/src/main/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStream.java
+++ b/beam/tools/src/main/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStream.java
@@ -717,27 +717,26 @@ public JoinInputs(
       }
       if (!windowingStrategy.equals(rightTmp.getWindowingStrategy())) {
         rightTmp =
-            (PCollection)
-                rightTmp.apply(
-                    createWindowTransform(
-                        (WindowingStrategy<RIGHT, ?>) windowingStrategy, triggerSupplier.get()));
+            rightTmp.apply(
+                createWindowTransform(
+                    (WindowingStrategy<RIGHT, ?>) windowingStrategy, triggerSupplier.get()));
       }
       TypeDescriptor<K> keyType = TypeDescriptor.of(Types.returnClass(leftKeyDehydrated));
       Coder<K> keyCoder = getCoder(pipeline, keyType);
+      this.leftCoder = leftTmp.getCoder();
+      this.rightCoder = rightTmp.getCoder();
       this.leftKv =
           leftTmp
               .apply(
                   MapElements.into(TypeDescriptors.kvs(keyType, leftTmp.getTypeDescriptor()))
                       .via(e -> KV.of(leftKeyDehydrated.call(e), e)))
-              .setCoder(KvCoder.of(keyCoder, leftTmp.getCoder()));
+              .setCoder(KvCoder.of(keyCoder, leftCoder));
       this.rightKv =
           rightTmp
               .apply(
                   MapElements.into(TypeDescriptors.kvs(keyType, rightTmp.getTypeDescriptor()))
                       .via(e -> KV.of(rightKeyDehydrated.call(e), e)))
-              .setCoder(KvCoder.of(keyCoder, rightTmp.getCoder()));
-      this.leftCoder = leftTmp.getCoder();
-      this.rightCoder = rightTmp.getCoder();
+              .setCoder(KvCoder.of(keyCoder, rightCoder));
     }
   }
 
diff --git a/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamStreamTest.java b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamStreamTest.java
index 7c4d534fe..c4a3fa508 100644
--- a/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamStreamTest.java
+++ b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamStreamTest.java
@@ -74,9 +74,11 @@
 import java.util.stream.Collectors;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.beam.runners.direct.DirectOptions;
+import org.apache.beam.runners.direct.DirectRunner;
 import org.apache.beam.runners.flink.FlinkRunner;
 import org.apache.beam.runners.spark.SparkRunner;
 import org.apache.beam.sdk.Pipeline;
+import org.apache.beam.sdk.PipelineRunner;
 import org.apache.beam.sdk.coders.Coder;
 import org.apache.beam.sdk.coders.KvCoder;
 import org.apache.beam.sdk.coders.StringUtf8Coder;
@@ -143,6 +145,10 @@ public void tearDown() {
   }
 
   static TestStreamProvider provider(boolean stream) {
+    return provider(stream, DirectRunner.class);
+  }
+
+  static TestStreamProvider provider(boolean stream, Class<? extends PipelineRunner<?>> runner) {
     return new TestStreamProvider() {
       @SuppressWarnings("unchecked")
       @Override
@@ -167,6 +173,11 @@ public <T> Stream<T> of(List<T> values) {
                 () -> {
                   LockSupport.park();
                   return false;
+                },
+                () -> {
+                  Pipeline p = BeamStream.createPipelineDefault();
+                  p.getOptions().setRunner(runner);
+                  return p;
                 }));
       }
     };
diff --git a/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamDirectTest.java b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamDirectTest.java
new file mode 100644
index 000000000..6dcc56795
--- /dev/null
+++ b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamDirectTest.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017-2023 O2 Czech Republic, a.s.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package cz.o2.proxima.beam.tools.groovy;
+
+import cz.o2.proxima.tools.groovy.WindowedStreamTest;
+import org.apache.beam.runners.direct.DirectRunner;
+import org.apache.beam.sdk.PipelineRunner;
+
+public class BeamWindowedStreamDirectTest extends WindowedStreamTest {
+
+  public BeamWindowedStreamDirectTest() {
+    this(DirectRunner.class);
+  }
+
+  protected BeamWindowedStreamDirectTest(Class<? extends PipelineRunner<?>> runner) {
+    super(BeamStreamTest.provider(true, runner));
+  }
+}
diff --git a/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamTest.java b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamFlinkTest.java
similarity index 76%
rename from beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamTest.java
rename to beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamFlinkTest.java
index be5177e73..dec09333e 100644
--- a/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamTest.java
+++ b/beam/tools/src/test/java/cz/o2/proxima/beam/tools/groovy/BeamWindowedStreamFlinkTest.java
@@ -15,11 +15,11 @@
  */
 package cz.o2.proxima.beam.tools.groovy;
 
-import cz.o2.proxima.tools.groovy.WindowedStreamTest;
+import org.apache.beam.runners.flink.FlinkRunner;
 
-public class BeamWindowedStreamTest extends WindowedStreamTest {
+public class BeamWindowedStreamFlinkTest extends BeamWindowedStreamDirectTest {
 
-  public BeamWindowedStreamTest() {
-    super(BeamStreamTest.provider(true));
+  public BeamWindowedStreamFlinkTest() {
+    super(FlinkRunner.class);
   }
 }
diff --git a/tools/src/main/java/cz/o2/proxima/tools/groovy/WindowedStream.java b/tools/src/main/java/cz/o2/proxima/tools/groovy/WindowedStream.java
index 69355c0d7..f297c9c51 100644
--- a/tools/src/main/java/cz/o2/proxima/tools/groovy/WindowedStream.java
+++ b/tools/src/main/java/cz/o2/proxima/tools/groovy/WindowedStream.java
@@ -316,7 +316,7 @@ <K> WindowedStream<Pair<K, Double>> averageByKey(
   default <K, OTHER> WindowedStream<Pair<T, OTHER>> join(
       WindowedStream<OTHER> right,
       @ClosureParams(value = FromString.class, options = "T") Closure<K> leftKey,
-      @ClosureParams(value = FromString.class, options = "T") Closure<K> rightKey) {
+      @ClosureParams(value = FromString.class, options = "OTHER") Closure<K> rightKey) {
 
     return join(null, right, leftKey, rightKey);
   }
@@ -336,7 +336,7 @@ <K, OTHER> WindowedStream<Pair<T, OTHER>> join(
       @Nullable String name,
       WindowedStream<OTHER> right,
       @ClosureParams(value = FromString.class, options = "T") Closure<K> leftKey,
-      @ClosureParams(value = FromString.class, options = "T") Closure<K> rightKey);
+      @ClosureParams(value = FromString.class, options = "OTHER") Closure<K> rightKey);
 
   /**
    * Left join with other stream.
@@ -351,7 +351,7 @@ <K, OTHER> WindowedStream<Pair<T, OTHER>> join(
   default <K, OTHER> WindowedStream<Pair<T, OTHER>> leftJoin(
       WindowedStream<OTHER> right,
       @ClosureParams(value = FromString.class, options = "T") Closure<K> leftKey,
-      @ClosureParams(value = FromString.class, options = "T") Closure<K> rightKey) {
+      @ClosureParams(value = FromString.class, options = "OTHER") Closure<K> rightKey) {
 
     return leftJoin(null, right, leftKey, rightKey);
   }
@@ -371,7 +371,7 @@ <K, OTHER> WindowedStream<Pair<T, OTHER>> leftJoin(
       @Nullable String name,
       WindowedStream<OTHER> right,
       @ClosureParams(value = FromString.class, options = "T") Closure<K> leftKey,
-      @ClosureParams(value = FromString.class, options = "T") Closure<K> rightKey);
+      @ClosureParams(value = FromString.class, options = "OTHER") Closure<K> rightKey);
 
   /**
    * Sort stream.