diff --git a/opentelemetry_distro_solarwinds/propagator.py b/opentelemetry_distro_solarwinds/propagator.py
index b11d50ee5..46b578dd1 100644
--- a/opentelemetry_distro_solarwinds/propagator.py
+++ b/opentelemetry_distro_solarwinds/propagator.py
@@ -74,14 +74,16 @@ def inject(
         context: typing.Optional[Context] = None,
         setter: textmap.Setter = textmap.default_setter,
     ) -> None:
-        """Injects sw tracestate and trace options from SpanContext into carrier for HTTP request"""
+        """Injects sw tracestate from carrier into carrier for HTTP request, to get
+        tracestate injected by previous propagators"""
         span = trace.get_current_span(context)
         span_context = span.get_span_context()
-        trace_state = span_context.trace_state
         sw_value = W3CTransformer.sw_from_context(span_context)
+        trace_state_header = carrier.get(self._TRACESTATE_HEADER_NAME, None)
 
-        # Prepare carrier with context's or new tracestate
-        if trace_state:
+        # Prepare carrier with carrier's or new tracestate
+        if trace_state_header:
+            trace_state = TraceState.from_header([trace_state_header])
             # Check if trace_state already contains sw KV
             if SW_TRACESTATE_KEY in trace_state.keys():
                 # If so, modify current span_id and trace_flags, and move to beginning of list
diff --git a/opentelemetry_distro_solarwinds/sampler.py b/opentelemetry_distro_solarwinds/sampler.py
index a4610d28e..378e2ab49 100644
--- a/opentelemetry_distro_solarwinds/sampler.py
+++ b/opentelemetry_distro_solarwinds/sampler.py
@@ -348,9 +348,9 @@ def calculate_attributes(
             trace_state_no_response = self.remove_response_from_sw(trace_state)
         else:
             # Must retain all potential tracestate pairs for attributes
-            attr_trace_state = TraceState.from_header(
+            attr_trace_state = TraceState.from_header([
                 tracestate_capture
-            )
+            ])
             new_attr_trace_state = attr_trace_state.update(
                 SW_TRACESTATE_KEY,
                 W3CTransformer.sw_from_span_and_decision(