diff --git a/temporal-sdk/src/test/java/io/temporal/workflow/signalTests/SignalHeaderTest.java b/temporal-sdk/src/test/java/io/temporal/workflow/signalTests/SignalHeaderTest.java
new file mode 100644
index 0000000000..9f3fc16ed0
--- /dev/null
+++ b/temporal-sdk/src/test/java/io/temporal/workflow/signalTests/SignalHeaderTest.java
@@ -0,0 +1,128 @@
+package io.temporal.workflow.signalTests;
+
+import static org.junit.Assert.assertEquals;
+
+import com.google.protobuf.ByteString;
+import io.temporal.api.common.v1.Payload;
+import io.temporal.client.WorkflowClientOptions;
+import io.temporal.client.WorkflowStub;
+import io.temporal.common.interceptors.Header;
+import io.temporal.common.interceptors.WorkerInterceptorBase;
+import io.temporal.common.interceptors.WorkflowClientCallsInterceptor;
+import io.temporal.common.interceptors.WorkflowClientCallsInterceptor.WorkflowSignalInput;
+import io.temporal.common.interceptors.WorkflowClientCallsInterceptor.WorkflowSignalOutput;
+import io.temporal.common.interceptors.WorkflowClientCallsInterceptorBase;
+import io.temporal.common.interceptors.WorkflowClientInterceptorBase;
+import io.temporal.common.interceptors.WorkflowInboundCallsInterceptor;
+import io.temporal.common.interceptors.WorkflowInboundCallsInterceptor.SignalInput;
+import io.temporal.common.interceptors.WorkflowInboundCallsInterceptorBase;
+import io.temporal.testing.internal.SDKTestWorkflowRule;
+import io.temporal.worker.WorkerFactoryOptions;
+import io.temporal.workflow.SignalMethod;
+import io.temporal.workflow.Workflow;
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
+import org.junit.Rule;
+import org.junit.Test;
+
+/**
+ * Verifies that headers attached to a signal by a client interceptor reach the inbound workflow
+ * interceptor when running against the (time-skipping) test server. Regression test for the test
+ * server dropping the header while building the WorkflowExecutionSignaled event.
+ */
+public class SignalHeaderTest {
+
+  private static final String HEADER_KEY = "signal-header-key";
+  private static final String HEADER_VALUE = "signal-header-value";
+  private static final AtomicReference<String> RECEIVED_HEADER = new AtomicReference<>();
+
+  @Rule
+  public SDKTestWorkflowRule testWorkflowRule =
+      SDKTestWorkflowRule.newBuilder()
+          .setWorkflowTypes(TestSignalWorkflowImpl.class)
+          .setWorkflowClientOptions(
+              WorkflowClientOptions.newBuilder()
+                  .setInterceptors(new SignalHeaderClientInterceptor())
+                  .validateAndBuildWithDefaults())
+          .setWorkerFactoryOptions(
+              WorkerFactoryOptions.newBuilder()
+                  .setWorkerInterceptors(new SignalHeaderWorkerInterceptor())
+                  .validateAndBuildWithDefaults())
+          .build();
+
+  @Test
+  public void headerIsPropagatedToInboundSignalHandler() {
+    TestSignalWorkflow workflow = testWorkflowRule.newWorkflowStub(TestSignalWorkflow.class);
+    WorkflowStub stub = WorkflowStub.fromTyped(workflow);
+    stub.start();
+    workflow.unblock();
+    stub.getResult(Void.class);
+    assertEquals(HEADER_VALUE, RECEIVED_HEADER.get());
+  }
+
+  @WorkflowInterface
+  public interface TestSignalWorkflow {
+    @WorkflowMethod
+    void execute();
+
+    @SignalMethod
+    void unblock();
+  }
+
+  public static class TestSignalWorkflowImpl implements TestSignalWorkflow {
+    private boolean unblocked = false;
+
+    @Override
+    public void execute() {
+      Workflow.await(() -> unblocked);
+    }
+
+    @Override
+    public void unblock() {
+      unblocked = true;
+    }
+  }
+
+  /** Adds a header to the outbound signal. */
+  private static class SignalHeaderClientInterceptor extends WorkflowClientInterceptorBase {
+    @Override
+    public WorkflowClientCallsInterceptor workflowClientCallsInterceptor(
+        WorkflowClientCallsInterceptor next) {
+      return new WorkflowClientCallsInterceptorBase(next) {
+        @Override
+        public WorkflowSignalOutput signal(WorkflowSignalInput input) {
+          Map<String, Payload> values = new HashMap<>(input.getHeader().getValues());
+          values.put(
+              HEADER_KEY,
+              Payload.newBuilder().setData(ByteString.copyFromUtf8(HEADER_VALUE)).build());
+          return super.signal(
+              new WorkflowSignalInput(
+                  input.getWorkflowExecution(),
+                  input.getSignalName(),
+                  new Header(values),
+                  input.getArguments()));
+        }
+      };
+    }
+  }
+
+  /** Captures the header seen by the inbound signal handler. */
+  private static class SignalHeaderWorkerInterceptor extends WorkerInterceptorBase {
+    @Override
+    public WorkflowInboundCallsInterceptor interceptWorkflow(WorkflowInboundCallsInterceptor next) {
+      return new WorkflowInboundCallsInterceptorBase(next) {
+        @Override
+        public void handleSignal(SignalInput input) {
+          Payload payload = input.getHeader().getValues().get(HEADER_KEY);
+          if (payload != null) {
+            RECEIVED_HEADER.set(payload.getData().toStringUtf8());
+          }
+          super.handleSignal(input);
+        }
+      };
+    }
+  }
+}
diff --git a/temporal-test-server/src/main/java/io/temporal/internal/testservice/TestWorkflowMutableStateImpl.java b/temporal-test-server/src/main/java/io/temporal/internal/testservice/TestWorkflowMutableStateImpl.java
index 19c7376ee7..804cf7906c 100644
--- a/temporal-test-server/src/main/java/io/temporal/internal/testservice/TestWorkflowMutableStateImpl.java
+++ b/temporal-test-server/src/main/java/io/temporal/internal/testservice/TestWorkflowMutableStateImpl.java
@@ -3625,6 +3625,9 @@ private void addExecutionSignaledEvent(
             .setIdentity(signalRequest.getIdentity())
             .setInput(signalRequest.getInput())
             .setSignalName(signalRequest.getSignalName());
+    if (signalRequest.hasHeader()) {
+      a.setHeader(signalRequest.getHeader());
+    }
 
     HistoryEvent.Builder event =
         HistoryEvent.newBuilder()