diff --git a/src/clientmon.cpp b/src/clientmon.cpp
index c1cb9ae..8bf249d 100644
--- a/src/clientmon.cpp
+++ b/src/clientmon.cpp
@@ -26,8 +26,8 @@ struct Entry {
     Value val;
     std::exception_ptr exc;
     Entry() = default;
-    Entry(Value&& v) :val(std::move(v)) {}
-    Entry(const std::exception_ptr& e) :exc(e) {}
+    explicit Entry(Value&& v) :val(std::move(v)) {}
+    explicit Entry(const std::exception_ptr& e) :exc(e) {}
 };
 }
 
@@ -75,7 +75,7 @@ struct SubscriptionImpl final : public OperationBase, public Subscription
 
     INST_COUNTER(SubscriptionImpl);
 
-    SubscriptionImpl(const evbase& loop)
+    explicit SubscriptionImpl(const evbase& loop)
         :OperationBase (Operation::Monitor, loop)
         ,ackTick(__FILE__, __LINE__,
                  event_new(loop.base, -1, EV_TIMEOUT, &tickAckS, this))
diff --git a/src/dataimpl.h b/src/dataimpl.h
index 6c7e16d..1e6c71c 100644
--- a/src/dataimpl.h
+++ b/src/dataimpl.h
@@ -118,6 +118,9 @@ struct FieldStorage {
 
     void init(StoreType code);
     void deinit();
+    FieldStorage() = default;
+    FieldStorage(const FieldStorage&) = delete;
+    FieldStorage& operator=(const FieldStorage&) = delete;
     ~FieldStorage();
 
     size_t index() const;
diff --git a/src/evhelper.h b/src/evhelper.h
index d1a3917..3509165 100644
--- a/src/evhelper.h
+++ b/src/evhelper.h
@@ -88,14 +88,16 @@ struct owned_ptr : public std::unique_ptr<T>
  */
 namespace mdetail {
 struct PVXS_API VFunctor0 {
+    VFunctor0() = default;
+    VFunctor0(VFunctor0&) = delete;
+    VFunctor0(const VFunctor0&) = delete;
+    VFunctor0& operator=(const VFunctor0&) = delete;
     virtual ~VFunctor0() =0;
     virtual void invoke() =0;
 };
 template<typename Fn>
 struct Functor0 : public VFunctor0 {
     Functor0() = default;
-    Functor0(const Functor0&) = delete;
-    Functor0(Functor0&&) = default;
     Functor0(Fn&& fn) : fn(std::move(fn)) {}
     virtual ~Functor0() {}
 
diff --git a/src/pvaproto.h b/src/pvaproto.h
index 17f0dcc..f090d7e 100644
--- a/src/pvaproto.h
+++ b/src/pvaproto.h
@@ -47,6 +47,8 @@ protected:
     constexpr Buffer(bool be, uint8_t* buf, size_t n) :pos(buf), limit(buf+n), be(be) {}
     virtual ~Buffer() {}
 public:
+    Buffer(const Buffer&) = delete;
+    Buffer& operator=(const Buffer&) = delete;
     bool be;
 
     // all sub-classes define
diff --git a/src/pvxs/client.h b/src/pvxs/client.h
index c449fac..2a5383e 100644
--- a/src/pvxs/client.h
+++ b/src/pvxs/client.h
@@ -174,6 +174,9 @@ struct SubscriptionStat {
 
 //! Handle for monitor subscription
 struct PVXS_API Subscription {
+    Subscription() = default;
+    Subscription(const Subscription&) = delete;
+    Subscription& operator=(const Subscription&) = delete;
     virtual ~Subscription() =0;
 
 protected:
diff --git a/src/pvxs/netcommon.h b/src/pvxs/netcommon.h
index 367d330..4492af2 100644
--- a/src/pvxs/netcommon.h
+++ b/src/pvxs/netcommon.h
@@ -63,6 +63,9 @@ struct Report {
 };
 
 struct PVXS_API ReportInfo {
+    ReportInfo() = default;
+    ReportInfo(const ReportInfo&) = delete;
+    ReportInfo& operator=(const ReportInfo&) = delete;
     virtual ~ReportInfo();
 };
 
diff --git a/src/pvxs/srvcommon.h b/src/pvxs/srvcommon.h
index a13ffd2..4f11e38 100644
--- a/src/pvxs/srvcommon.h
+++ b/src/pvxs/srvcommon.h
@@ -82,6 +82,8 @@ public:
         ,_cred(cred)
         ,_op(op)
     {}
+    OpBase(const OpBase&) = delete;
+    OpBase& operator=(const OpBase&) = delete;
     virtual ~OpBase() =0;
 };
 
@@ -110,6 +112,8 @@ public:
         :OpBase(name, cred, op)
         ,_pvRequest(pvRequest)
     {}
+    ExecOp(const ExecOp&) = delete;
+    ExecOp& operator=(const ExecOp&) = delete;
     virtual ~ExecOp();
 
 #ifdef PVXS_EXPERT_API_ENABLED
diff --git a/src/udp_collector.h b/src/udp_collector.h
index 6fcb8fd..df8a89b 100644
--- a/src/udp_collector.h
+++ b/src/udp_collector.h
@@ -66,6 +66,9 @@ struct PVXS_API UDPManager
         decltype (names)::const_iterator end() const   { return names.end(); }
 
         virtual bool reply(const void *msg, size_t msglen) const =0;
+        Search() = default;
+        Search(const Search&) = delete;
+        Search& operator=(const Search&) = delete;
         virtual ~Search();
     };
     //! Create subscription for Search messages.
diff --git a/src/util.cpp b/src/util.cpp
index 43ba7c6..038c470 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -269,6 +269,8 @@ struct SocketPair {
     SocketPair() {
         compat_socketpair(s);
     }
+    SocketPair(const SocketPair&) = delete;
+    SocketPair& operator=(const SocketPair&) = delete;
     ~SocketPair() {
         epicsSocketDestroy(s[0]);
         epicsSocketDestroy(s[1]);
diff --git a/src/utilpvt.h b/src/utilpvt.h
index bc23323..5809c95 100644
--- a/src/utilpvt.h
+++ b/src/utilpvt.h
@@ -260,6 +260,8 @@ struct Restore {
         ,pfill(strm.fill())
         ,pwidth(strm.width())
     {}
+    Restore(const Restore&) = delete;
+    Restore& operator=(const Restore&) = delete;
     ~Restore() {
         strm.flags(pflags);
         strm.fill(pfill);
@@ -278,6 +280,8 @@ struct InstCounter {
             registerICount(Name, Cnt);
         }
     }
+    InstCounter(const InstCounter&) = delete;
+    InstCounter& operator=(const InstCounter&) = delete;
     ~InstCounter() {
         Cnt.fetch_sub(1u, std::memory_order_relaxed);
     }