diff --git a/src/hotspot/share/prims/jvmtiEnvBase.cpp b/src/hotspot/share/prims/jvmtiEnvBase.cpp
index a19e747f767..ec4beb3594d 100644
--- a/src/hotspot/share/prims/jvmtiEnvBase.cpp
+++ b/src/hotspot/share/prims/jvmtiEnvBase.cpp
@@ -213,7 +213,8 @@ JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
   _is_retransformable = true;
 
   // all callbacks initially null
-  memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
+  memset(&_event_callbacks, 0, sizeof(jvmtiEventCallbacks));
+  memset(&_ext_event_callbacks, 0, sizeof(jvmtiExtEventCallbacks));
 
   // all capabilities initially off
   memset(&_current_capabilities, 0, sizeof(_current_capabilities));