diff --git a/pkg/sentry/kernel/memevent/memory_events.go b/pkg/sentry/kernel/memevent/memory_events.go
index ecc9151de..f7a183a1d 100644
--- a/pkg/sentry/kernel/memevent/memory_events.go
+++ b/pkg/sentry/kernel/memevent/memory_events.go
@@ -94,5 +94,8 @@ func (m *MemoryEvents) emit() {
 	snapshot, _ := usage.MemoryAccounting.Copy()
 	total := totalPlatform + snapshot.Mapped
 
-	eventchannel.Emit(&pb.MemoryUsageEvent{Total: total})
+	eventchannel.Emit(&pb.MemoryUsageEvent{
+		Mapped: snapshot.Mapped,
+		Total:  total,
+	})
 }
diff --git a/pkg/sentry/kernel/memevent/memory_events.proto b/pkg/sentry/kernel/memevent/memory_events.proto
index e6e0bd628..abc565054 100644
--- a/pkg/sentry/kernel/memevent/memory_events.proto
+++ b/pkg/sentry/kernel/memevent/memory_events.proto
@@ -22,4 +22,8 @@ message MemoryUsageEvent {
   // The total memory usage of the sandboxed application in bytes, calculated
   // using the 'fast' method.
   uint64 total = 1;
+
+  // Memory used to back memory-mapped regions for files in the application, in
+  // bytes. This corresponds to the usage.MemoryKind.Mapped memory type.
+  uint64 mapped = 2;
 }