diff --git a/opentracing-flowid/opentracing-flowid/src/main/java/org/zalando/opentracing/flowid/DefaultFlow.java b/opentracing-flowid/opentracing-flowid/src/main/java/org/zalando/opentracing/flowid/DefaultFlow.java
index 5417822c..f28bba7b 100644
--- a/opentracing-flowid/opentracing-flowid/src/main/java/org/zalando/opentracing/flowid/DefaultFlow.java
+++ b/opentracing-flowid/opentracing-flowid/src/main/java/org/zalando/opentracing/flowid/DefaultFlow.java
@@ -59,7 +59,10 @@ public String currentId() {
 
     @Override
     public void writeTo(final BiConsumer<String, String> writer) {
-        writer.accept(Header.FLOW_ID, currentId());
+        extractor.extract(activeSpan())
+                .map(FlowId::getValue)
+                .ifPresent(value ->
+                        writer.accept(Header.FLOW_ID, value));
     }
 
     @Override
diff --git a/opentracing-flowid/opentracing-flowid/src/test/java/org/zalando/opentracing/flowid/DefaultFlowNoopTracerTest.java b/opentracing-flowid/opentracing-flowid/src/test/java/org/zalando/opentracing/flowid/DefaultFlowNoopTracerTest.java
index 6050acad..5fd7c353 100644
--- a/opentracing-flowid/opentracing-flowid/src/test/java/org/zalando/opentracing/flowid/DefaultFlowNoopTracerTest.java
+++ b/opentracing-flowid/opentracing-flowid/src/test/java/org/zalando/opentracing/flowid/DefaultFlowNoopTracerTest.java
@@ -3,6 +3,11 @@
 import io.opentracing.noop.NoopTracerFactory;
 import org.junit.jupiter.api.Test;
 
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.util.Collections.emptyMap;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class DefaultFlowNoopTracerTest {
@@ -12,4 +17,11 @@ class DefaultFlowNoopTracerTest {
     void shouldThrowNoActiveSpanFoundException() {
         assertThrows(IllegalStateException.class, unit::currentId);
     }
+
+    @Test
+    void writeToShouldNotThrow() {
+        final Map<String, String> target = new HashMap<>();
+        unit.writeTo(target::put);
+        assertEquals(emptyMap(), target);
+    }
 }