diff --git a/src/datadog/tags.cpp b/src/datadog/tags.cpp
index 4b2bc997..ddeca213 100644
--- a/src/datadog/tags.cpp
+++ b/src/datadog/tags.cpp
@@ -36,6 +36,7 @@ const std::string w3c_parent_id = "_dd.parent_id";
 const std::string trace_source = "_dd.p.ts";
 const std::string apm_enabled = "_dd.apm.enabled";
 const std::string ksr = "_dd.p.ksr";
+const std::string sdk_otlp_export = "_dd.sdk.otlp_export";
 
 }  // namespace internal
 
diff --git a/src/datadog/tags.h b/src/datadog/tags.h
index 8d9f4d60..0c282693 100644
--- a/src/datadog/tags.h
+++ b/src/datadog/tags.h
@@ -41,9 +41,10 @@ extern const std::string process_id;
 extern const std::string language;
 extern const std::string runtime_id;
 extern const std::string w3c_parent_id;
-extern const std::string trace_source;  // _dd.p.ts
-extern const std::string apm_enabled;   // _dd.apm.enabled
-extern const std::string ksr;           // _dd.p.ksr
+extern const std::string trace_source;     // _dd.p.ts
+extern const std::string apm_enabled;      // _dd.apm.enabled
+extern const std::string ksr;              // _dd.p.ksr
+extern const std::string sdk_otlp_export;  // _dd.sdk.otlp_export
 
 }  // namespace internal
 
diff --git a/src/datadog/trace_segment.cpp b/src/datadog/trace_segment.cpp
index fc70445c..fa0f8965 100644
--- a/src/datadog/trace_segment.cpp
+++ b/src/datadog/trace_segment.cpp
@@ -371,6 +371,8 @@ void TraceSegment::span_finished() {
   if (hostname_) {
     local_root.tags[tags::internal::hostname] = *hostname_;
   }
+  // Mark the chunk as sent in Datadog format, not OTLP. One per chunk.
+  local_root.tags[tags::internal::sdk_otlp_export] = "false";
   if (decision.origin == SamplingDecision::Origin::LOCAL) {
     if (decision.mechanism == int(SamplingMechanism::AGENT_RATE) ||
         decision.mechanism == int(SamplingMechanism::DEFAULT)) {
diff --git a/test/test_trace_segment.cpp b/test/test_trace_segment.cpp
index 37f8f94a..f89370ab 100644
--- a/test/test_trace_segment.cpp
+++ b/test/test_trace_segment.cpp
@@ -289,6 +289,22 @@ TEST_CASE("TraceSegment finalization of spans") {
               get_hostname());
     }
 
+    SECTION("OTLP export marker is on the first span of the chunk only") {
+      auto finalized = finalize_config(config);
+      REQUIRE(finalized);
+      Tracer tracer{*finalized};
+      {
+        auto root = tracer.create_span();
+        auto child = root.create_child();
+        (void)child;
+      }
+      REQUIRE(collector->chunks.size() == 1);
+      const auto& chunk = collector->chunks.front();
+      REQUIRE(chunk.size() == 2);
+      REQUIRE(chunk[0]->tags.at(tags::internal::sdk_otlp_export) == "false");
+      REQUIRE(chunk[1]->tags.count(tags::internal::sdk_otlp_export) == 0);
+    }
+
     SECTION("x-datadog-tags") {
       auto finalized = finalize_config(config);
       REQUIRE(finalized);