diff --git a/api/include/opentelemetry/trace/trace_state.h b/api/include/opentelemetry/trace/trace_state.h
index 8a25f4da5c..f51410025a 100644
--- a/api/include/opentelemetry/trace/trace_state.h
+++ b/api/include/opentelemetry/trace/trace_state.h
@@ -95,7 +95,7 @@ class OPENTELEMETRY_EXPORT TraceState
         [&header_s, &first](nostd::string_view key, nostd::string_view value) noexcept {
           if (!first)
           {
-            header_s.append(",");
+            header_s.append(1, kMembersSeparator);
           }
           else
           {