diff --git a/src/debugger.cc b/src/debugger.cc
index 5b8c32c..a858962 100644
--- a/src/debugger.cc
+++ b/src/debugger.cc
@@ -420,8 +420,7 @@
 }
 
 int64_t Dbg::LastDebuggerActivity() {
-  UNIMPLEMENTED(WARNING);
-  return -1;
+  return gJdwpState->LastDebuggerActivity();
 }
 
 int Dbg::ThreadRunning() {