diff --git a/examples/tiny-nghttpd.c b/examples/tiny-nghttpd.c
index 79fc0c46..037155e3 100644
--- a/examples/tiny-nghttpd.c
+++ b/examples/tiny-nghttpd.c
@@ -422,7 +422,11 @@ static int server_init(server *serv, const char *node, const char *service)
       continue;
     }
 
-    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, optlen);
+    rv = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, optlen);
+
+    if(rv == -1) {
+      print_errno("setsockopt", errno);
+    }
 
     if(bind(fd, rp->ai_addr, rp->ai_addrlen) != 0) {
       close(fd);
@@ -552,7 +556,10 @@ static int handle_timer(io_loop *loop, uint32_t events, void *ptr)
     ssize_t nread;
 
     while((nread = read(tmr->fd, buf, sizeof(buf))) == -1 && errno == EINTR);
-    break;
+
+    if(nread == -1) {
+      break;
+    }
   }
 
   update_date();
@@ -566,6 +573,7 @@ static int handle_accept(io_loop *loop, uint32_t events, void *ptr)
   server *serv = ptr;
   int on = 1;
   socklen_t optlen = sizeof(on);
+  int rv;
 
   for(;;) {
     connection *conn;
@@ -574,7 +582,7 @@ static int handle_accept(io_loop *loop, uint32_t events, void *ptr)
           errno == EINTR);
 
     if(acfd == -1) {
-      switch(acfd) {
+      switch(errno) {
       case ENETDOWN:
       case EPROTO:
       case ENOPROTOOPT:
@@ -588,7 +596,11 @@ static int handle_accept(io_loop *loop, uint32_t events, void *ptr)
       return 0;
     }
 
-    setsockopt(acfd, IPPROTO_TCP, TCP_NODELAY, &on, optlen);
+    rv = setsockopt(acfd, IPPROTO_TCP, TCP_NODELAY, &on, optlen);
+
+    if(rv == -1) {
+      print_errno("setsockopt", errno);
+    }
 
     conn = connection_new(acfd);
 
diff --git a/src/HttpServer.cc b/src/HttpServer.cc
index 25ff748b..7bfc24d3 100644
--- a/src/HttpServer.cc
+++ b/src/HttpServer.cc
@@ -122,6 +122,11 @@ Config::Config()
   nghttp2_option_set_recv_client_preface(session_option, 1);
 }
 
+Config::~Config()
+{
+  nghttp2_option_del(session_option);
+}
+
 Stream::Stream(Http2Handler *handler, int32_t stream_id)
   : handler(handler),
     rtimer(nullptr),
@@ -512,7 +517,9 @@ int Http2Handler::on_read()
       return -1;
     }
 
-    evbuffer_drain(input, len);
+    if(evbuffer_drain(input, len) == -1) {
+      std::cerr << "evbuffer_drain() failed" << std::endl;
+    }
   }
 
   return send();
@@ -1268,7 +1275,9 @@ void worker_readcb(bufferevent *bev, void *arg)
   auto input = bufferevent_get_input(bev);
   while(evbuffer_get_length(input) >= sizeof(ClientInfo)) {
     ClientInfo client;
-    evbuffer_remove(input, &client, sizeof(client));
+    if(evbuffer_remove(input, &client, sizeof(client)) == -1) {
+      std::cerr << "evbuffer_remove() failed" << std::endl;
+    }
     sessions->accept_connection(client.fd);
   }
 }
diff --git a/src/HttpServer.h b/src/HttpServer.h
index 2b05f446..6c856113 100644
--- a/src/HttpServer.h
+++ b/src/HttpServer.h
@@ -80,6 +80,7 @@ struct Config {
   bool error_gzip;
   bool early_response;
   Config();
+  ~Config();
 };
 
 class Http2Handler;