diff --git a/src/Jaeger/Propagator/ZipkinPropagator.php b/src/Jaeger/Propagator/ZipkinPropagator.php
index 1c60632..39125c4 100644
--- a/src/Jaeger/Propagator/ZipkinPropagator.php
+++ b/src/Jaeger/Propagator/ZipkinPropagator.php
@@ -17,7 +17,7 @@ public function inject(SpanContext $spanContext, $format, &$carrier){
     public function extract($format, $carrier){
         $spanContext = new SpanContext(0, 0, 0, null, 0);
         if(isset($carrier[Constants\X_B3_TRACEID]) && $carrier[Constants\X_B3_TRACEID]){
-            $spanContext->traceIdLow = $spanContext->hexToSignedInt($carrier[Constants\X_B3_TRACEID]);
+            $spanContext->traceIdToString($carrier[Constants\X_B3_TRACEID]);
         }
 
         if(isset($carrier[Constants\X_B3_PARENT_SPANID]) && $carrier[Constants\X_B3_PARENT_SPANID]){
diff --git a/src/Jaeger/SpanContext.php b/src/Jaeger/SpanContext.php
index 38e1884..45c6cdf 100644
--- a/src/Jaeger/SpanContext.php
+++ b/src/Jaeger/SpanContext.php
@@ -76,6 +76,10 @@ public function parentIdToString(){
 
 
     public function traceIdLowToString(){
+        if ($this->traceIdHigh) {
+            return sprintf("%x%016x", $this->traceIdHigh, $this->traceIdLow);
+        }
+
         return sprintf("%x", $this->traceIdLow);
     }