diff --git a/src/net.h b/src/net.h
--- a/src/net.h
+++ b/src/net.h
@@ -295,7 +295,8 @@
 
     void PushMessage(CNode *pnode, CSerializedNetMsg &&msg);
 
-    template <typename Callable> void ForEachNode(Callable &&func) {
+    using NodeFn = std::function<void(CNode *)>;
+    void ForEachNode(const NodeFn &func) {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) {
@@ -304,7 +305,7 @@
         }
     };
 
-    template <typename Callable> void ForEachNode(Callable &&func) const {
+    void ForEachNode(const NodeFn &func) const {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) {