diff --git a/proto/v1/Span.proto b/proto/v1/Span.proto
index ebdabd3..a98cb85 100644
--- a/proto/v1/Span.proto
+++ b/proto/v1/Span.proto
@@ -22,8 +22,8 @@ message PSpan {
 
     PTransactionId transactionId = 2;
 
-    sfixed64 spanId = 3;
-    sfixed64 parentSpanId = 4;
+    sfixed64 spanId = 3 [jstype = JS_STRING];
+    sfixed64 parentSpanId = 4 [jstype = JS_STRING];
 
     // span event's startTimestamp
     int64 startTime = 5;
@@ -50,8 +50,8 @@ message PSpan {
 message PTransactionId {
     // identical to agentId if null
     string agentId = 1; //nullable
-    int64 agentStartTime = 2;
-    int64 sequence = 3;
+    int64 agentStartTime = 2 [jstype = JS_STRING];
+    int64 sequence = 3 [jstype = JS_STRING];
 }
 
 message PAcceptEvent {
@@ -108,7 +108,7 @@ message PSpanChunk {
 
     PTransactionId transactionId = 2;
 
-    sfixed64 spanId = 3;
+    sfixed64 spanId = 3 [jstype = JS_STRING];
 
     string endPoint = 4;