diff --git a/src/inspector/v8-inspector-session-impl.h b/src/inspector/v8-inspector-session-impl.h
index d323b47f3d8..9b782599498 100644
--- a/src/inspector/v8-inspector-session-impl.h
+++ b/src/inspector/v8-inspector-session-impl.h
@@ -56,6 +56,22 @@ class V8InspectorSessionImpl : public V8InspectorSession,
   int contextGroupId() const { return m_contextGroupId; }
   int sessionId() const { return m_sessionId; }
 
+  // Pins the session for the lifetime of the scope so re-entrant page JS that
+  // causes the embedder to drop its shared_ptr (e.g. DevToolsSession::Detach)
+  // cannot fully destroy the session while inspector code is still on the
+  // stack. Used by dispatchProtocolMessage and by entry points reached from
+  // V8 callbacks (console.log -> reportMessage).
+  class KeepSessionAliveScope {
+    CPPGC_STACK_ALLOCATED();
+
+   public:
+    explicit KeepSessionAliveScope(const V8InspectorSessionImpl& session)
+        : m_this(session.m_weakThis.lock()) {}
+
+   private:
+    std::shared_ptr<V8InspectorSessionImpl> m_this;
+  };
+
   Response findInjectedScript(
       int contextId, InjectedScript*&,
       std::shared_ptr<InspectedContext>* inspectedContext = nullptr);
@@ -156,20 +172,6 @@ class V8InspectorSessionImpl : public V8InspectorSession,
   bool use_binary_protocol_ = false;
   V8Inspector::ClientTrustLevel m_clientTrustLevel = V8Inspector::kUntrusted;
 
-  // On each call to "dispatchProtocolMessage", the session turns the weakThis
-  // reference into a strong one, so nested run loops are not able to fully
-  // deconstruct the V8 session until we return from the
-  // "dispatchProtocolMessage" call (i.e. no freed "this" remains on the stack).
-  class KeepSessionAliveScope {
-    CPPGC_STACK_ALLOCATED();
-
-   public:
-    explicit KeepSessionAliveScope(const V8InspectorSessionImpl& session)
-        : m_this(session.m_weakThis.lock()) {}
-
-   private:
-    std::shared_ptr<V8InspectorSessionImpl> m_this;
-  };
   std::weak_ptr<V8InspectorSessionImpl> m_weakThis;
 };
 
diff --git a/src/inspector/v8-runtime-agent-impl.cc b/src/inspector/v8-runtime-agent-impl.cc
index 226a6c74d94..941ba186ce9 100644
--- a/src/inspector/v8-runtime-agent-impl.cc
+++ b/src/inspector/v8-runtime-agent-impl.cc
@@ -1216,6 +1216,10 @@ void V8RuntimeAgentImpl::messageAdded(V8ConsoleMessage* message) {
 
 bool V8RuntimeAgentImpl::reportMessage(V8ConsoleMessage* message,
                                        bool generatePreview) {
+  // reportToFrontend may re-enter page JS (descriptionForError -> prototype
+  // getter) which can drop the embedder's last ref to the session. Pin it so
+  // |this| (owned by the session) survives until we return.
+  V8InspectorSessionImpl::KeepSessionAliveScope keep(*m_session);
   message->reportToFrontend(&m_frontend, m_session, generatePreview);
   m_frontend.flush();
   return m_inspector->hasConsoleMessageStorage(m_session->contextGroupId());