diff --git a/lib/netplay/tcp/tcp_client_connection.h b/lib/netplay/tcp/tcp_client_connection.h
index d8f45716a9d..c2d00959d7f 100644
--- a/lib/netplay/tcp/tcp_client_connection.h
+++ b/lib/netplay/tcp/tcp_client_connection.h
@@ -30,7 +30,7 @@ class TCPClientConnection : public IClientConnection
 {
 public:
 
-	TCPClientConnection(Socket* rawSocket);
+	explicit TCPClientConnection(Socket* rawSocket);
 	virtual ~TCPClientConnection() override;
 
 	virtual net::result<ssize_t> readAll(void* buf, size_t size, unsigned timeout) override;
diff --git a/lib/netplay/tcp/tcp_connection_poll_group.h b/lib/netplay/tcp/tcp_connection_poll_group.h
index 7146f0997dd..d9eec5bb909 100644
--- a/lib/netplay/tcp/tcp_connection_poll_group.h
+++ b/lib/netplay/tcp/tcp_connection_poll_group.h
@@ -30,7 +30,7 @@ class TCPConnectionPollGroup : public IConnectionPollGroup
 {
 public:
 
-	TCPConnectionPollGroup(SocketSet* sset);
+	explicit TCPConnectionPollGroup(SocketSet* sset);
 	virtual ~TCPConnectionPollGroup() override;
 
 	virtual int checkSockets(unsigned timeout) override;
diff --git a/lib/netplay/tcp/tcp_listen_socket.h b/lib/netplay/tcp/tcp_listen_socket.h
index 94602b5d031..db78b25a0df 100644
--- a/lib/netplay/tcp/tcp_listen_socket.h
+++ b/lib/netplay/tcp/tcp_listen_socket.h
@@ -32,7 +32,7 @@ class TCPListenSocket : public IListenSocket
 {
 public:
 
-	TCPListenSocket(tcp::Socket* rawSocket);
+	explicit TCPListenSocket(tcp::Socket* rawSocket);
 	virtual ~TCPListenSocket() override;
 
 	virtual IClientConnection* accept() override;