diff --git a/runtimes/google/testing/mocks/runtime/panic_runtime.go b/runtimes/google/testing/mocks/runtime/panic_runtime.go
new file mode 100644
index 0000000..87a9ee3
--- /dev/null
+++ b/runtimes/google/testing/mocks/runtime/panic_runtime.go
@@ -0,0 +1,50 @@
+package runtime
+
+import (
+	"veyron2"
+	"veyron2/config"
+	"veyron2/context"
+	"veyron2/ipc"
+	"veyron2/ipc/stream"
+	"veyron2/naming"
+	"veyron2/security"
+	"veyron2/vlog"
+	"veyron2/vtrace"
+)
+
+// PanicRuntime is a dummy implementation of veyron2.Runtime that panics on every
+// operation.  This is useful when you want to pass around a non-nil runtime
+// implementation but you don't want it to be used.
+type PanicRuntime struct {
+	unique int // Make non-empty to ensure pointer instances are unique.
+}
+
+const badRuntime = "The runtime implmentation should not call methods on runtime intances."
+
+func (*PanicRuntime) Profile() veyron2.Profile                               { panic(badRuntime) }
+func (*PanicRuntime) Publisher() *config.Publisher                           { panic(badRuntime) }
+func (*PanicRuntime) NewIdentity(name string) (security.PrivateID, error)    { panic(badRuntime) }
+func (*PanicRuntime) PublicIDStore() security.PublicIDStore                  { panic(badRuntime) }
+func (*PanicRuntime) Identity() security.PrivateID                           { panic(badRuntime) }
+func (*PanicRuntime) NewClient(opts ...ipc.ClientOpt) (ipc.Client, error)    { panic(badRuntime) }
+func (*PanicRuntime) NewServer(opts ...ipc.ServerOpt) (ipc.Server, error)    { panic(badRuntime) }
+func (*PanicRuntime) Client() ipc.Client                                     { panic(badRuntime) }
+func (*PanicRuntime) NewContext() context.T                                  { panic(badRuntime) }
+func (*PanicRuntime) WithNewSpan(context.T, string) (context.T, vtrace.Span) { panic(badRuntime) }
+func (*PanicRuntime) SpanFromContext(context.T) vtrace.Span                  { panic(badRuntime) }
+func (*PanicRuntime) NewStreamManager(opts ...stream.ManagerOpt) (stream.Manager, error) {
+	panic(badRuntime)
+}
+func (*PanicRuntime) NewEndpoint(ep string) (naming.Endpoint, error) { panic(badRuntime) }
+func (*PanicRuntime) Namespace() naming.Namespace                    { panic(badRuntime) }
+func (*PanicRuntime) Logger() vlog.Logger                            { panic(badRuntime) }
+func (*PanicRuntime) NewLogger(name string, opts ...vlog.LoggingOpts) (vlog.Logger, error) {
+	panic(badRuntime)
+}
+func (*PanicRuntime) Stop()                         { panic(badRuntime) }
+func (*PanicRuntime) ForceStop()                    { panic(badRuntime) }
+func (*PanicRuntime) WaitForStop(chan<- string)     { panic(badRuntime) }
+func (*PanicRuntime) AdvanceGoal(delta int)         { panic(badRuntime) }
+func (*PanicRuntime) AdvanceProgress(delta int)     { panic(badRuntime) }
+func (*PanicRuntime) TrackTask(chan<- veyron2.Task) { panic(badRuntime) }
+func (*PanicRuntime) Cleanup()                      { panic(badRuntime) }