diff --git a/opentracing-okhttp3/src/main/java/io/opentracing/contrib/okhttp3/RequestBuilderInjectAdapter.java b/opentracing-okhttp3/src/main/java/io/opentracing/contrib/okhttp3/RequestBuilderInjectAdapter.java
index 5ad0758..d8546a7 100644
--- a/opentracing-okhttp3/src/main/java/io/opentracing/contrib/okhttp3/RequestBuilderInjectAdapter.java
+++ b/opentracing-okhttp3/src/main/java/io/opentracing/contrib/okhttp3/RequestBuilderInjectAdapter.java
@@ -26,6 +26,6 @@ public Iterator<Map.Entry<String, String>> iterator() {
 
     @Override
     public void put(String key, String value) {
-        requestBuilder.addHeader(key, value);
+        requestBuilder.header(key, value);
     }
 }