diff --git a/src/clientdiscover.cpp b/src/clientdiscover.cpp
index 59721ed..f9dc438 100644
--- a/src/clientdiscover.cpp
+++ b/src/clientdiscover.cpp
@@ -21,7 +21,7 @@ Discovery::Discovery(const std::shared_ptr<ContextImpl> &context, const std::str
 {}
 
 Discovery::~Discovery() {
-    if(loop.assertInRunningLoop())
+    if(onWorker && loop.assertInRunningLoop())
         _cancel(true);
 }
 
@@ -81,6 +81,8 @@ std::shared_ptr<Operation> DiscoverBuilder::exec()
     // setup timer to send discovery
 
     context->tcp_loop.dispatch([op, context, ping]() {
+        // on worker
+        op->onWorker = true;
 
         if(context->state!=ContextImpl::Running)
             throw std::logic_error("Context close()d");
diff --git a/src/clientget.cpp b/src/clientget.cpp
index adaf396..59320b4 100644
--- a/src/clientget.cpp
+++ b/src/clientget.cpp
@@ -138,7 +138,7 @@ struct GPROp : public OperationBase
         :OperationBase (op, loop, name)
     {}
     ~GPROp() {
-        if(loop.assertInRunningLoop())
+        if(onWorker && loop.assertInRunningLoop())
             _cancel(true);
     }
 
@@ -605,6 +605,7 @@ std::shared_ptr<Operation> gpr_setup(const std::shared_ptr<ContextImpl>& context
 
     context->tcp_loop.dispatch([internal, context, name, server]() {
         // on worker
+        internal->onWorker = true;
 
         try {
             internal->chan = Channel::build(context, name, server);
diff --git a/src/clientimpl.h b/src/clientimpl.h
index b15fff9..0047a63 100644
--- a/src/clientimpl.h
+++ b/src/clientimpl.h
@@ -50,6 +50,8 @@ struct OperationBase : public Operation
     uint32_t ioid = 0;
     Value result;
     bool done = false;
+    // state of handoff from user thread to worker
+    bool onWorker = false;
     std::shared_ptr<ResultWaiter> waiter;
 
     OperationBase(operation_t op, const evbase& loop, const std::string& name);
diff --git a/src/clientmon.cpp b/src/clientmon.cpp
index fc45dc8..af5c422 100644
--- a/src/clientmon.cpp
+++ b/src/clientmon.cpp
@@ -84,7 +84,7 @@ struct SubscriptionImpl final : public OperationBase, public Subscription
                  event_new(loop.base, -1, EV_TIMEOUT, &tickAckS, this))
     {}
     virtual ~SubscriptionImpl() {
-        if(loop.assertInRunningLoop())
+        if(onWorker && loop.assertInRunningLoop())
             _cancel(true);
     }
 
@@ -830,6 +830,7 @@ std::shared_ptr<Subscription> MonitorBuilder::exec()
     auto server(std::move(_server));
     context->tcp_loop.dispatch([op, context, server]() {
         // on worker
+        op->onWorker = true;
 
         try {
             op->chan = Channel::build(context, op->channelName, server);
diff --git a/test/testget.cpp b/test/testget.cpp
index 7ddb336..dd35293 100644
--- a/test/testget.cpp
+++ b/test/testget.cpp
@@ -25,6 +25,16 @@
 namespace {
 using namespace pvxs;
 
+void testEmptyName() {
+    client::Config conf;
+    conf.autoAddrList = false;
+    auto ctx(conf.build());
+    testThrowsMatch<std::logic_error>("Empty channel name",
+                                      [&](){
+                                          ctx.get("").exec();
+                                      });
+}
+
 struct Tester {
     Value initial;
     server::SharedPV mbox;
@@ -592,10 +602,11 @@ void testServerClose()
 
 MAIN(testget)
 {
-    testPlan(67);
+    testPlan(68);
     testSetup();
     logger_config_env();
     const bool canIPv6 = pvxs::impl::evsocket::canIPv6;
+    testEmptyName();
     Tester().testConnector();
     Tester().testWaiter();
     Tester(AF_INET).loopback();