diff --git a/runtime/jdwp/jdwp_handler.cc b/runtime/jdwp/jdwp_handler.cc
index be34bd3..a39a7b7 100644
--- a/runtime/jdwp/jdwp_handler.cc
+++ b/runtime/jdwp/jdwp_handler.cc
@@ -1345,8 +1345,10 @@
       }
       break;
     default:
-      LOG(WARNING) << "GLITCH: unsupported modKind=" << mod.modKind;
-      break;
+      LOG(WARNING) << "Unsupported modifier " << mod.modKind << " for event " << pEvent->eventKind;
+      // Free allocated event to avoid leak before leaving.
+      EventFree(pEvent);
+      return JDWP::ERR_NOT_IMPLEMENTED;
     }
   }