diff --git a/apm-network/src/main/proto/JVMMetricsService.proto b/apm-network/src/main/proto/JVMMetricsService.proto
index 6e5973efbb83ff7e15d8cc178fb1113487d17640..4a32135d7b6833d4b9ddc0b55ec85a5f4bd8a6c2 100644
--- a/apm-network/src/main/proto/JVMMetricsService.proto
+++ b/apm-network/src/main/proto/JVMMetricsService.proto
@@ -12,7 +12,7 @@ service JVMMetricsService {
 
 message JVMMetrics {
     repeated JVMMetric metrics = 1;
-    int64 applicationInstanceId = 2;
+    int32 applicationInstanceId = 2;
 }
 
 message JVMMetric {