client.go                  | 2 +-
 client_test.go             | 2 +-
 dht/closest_nodes.go       | 2 +-
 tracker/udp/udp_tracker.go | 1 -

diff --git a/client.go b/client.go
index 15955a8057a65f8a974d97eca7d5a7f47a3c868b..0c3cdee45adbd67da31cf85e6aafab48d55805f0 100644
--- a/client.go
+++ b/client.go
@@ -717,7 +717,7 @@ 					}
 					log.Printf("added %d peers from PEX", len(pexMsg.Added))
 				}()
 			default:
-				err = fmt.Errorf("unexpected extended message ID: %s", msg.ExtendedID)
+				err = fmt.Errorf("unexpected extended message ID: %v", msg.ExtendedID)
 			}
 		default:
 			err = fmt.Errorf("received unknown message type: %#v", msg.Type)
diff --git a/client_test.go b/client_test.go
index d3dd01569f4d5b7cc404b0844e88ac0d9dc99be0..835ad1f175975d0588ac3c2c0fc3578e701d5dda 100644
--- a/client_test.go
+++ b/client_test.go
@@ -41,7 +41,7 @@ 		t.Fatal("wrong number of pieces")
 	}
 	p := tor.Pieces[0]
 	if len(p.PendingChunkSpecs) != 1 {
-		t.Fatalf("should only be 1 chunk: %s", p.PendingChunkSpecs)
+		t.Fatalf("should only be 1 chunk: %v", p.PendingChunkSpecs)
 	}
 	if _, ok := p.PendingChunkSpecs[chunkSpec{
 		Length: 13,
diff --git a/dht/closest_nodes.go b/dht/closest_nodes.go
index 2f98e6d6c38d15fcf5de5fec6d0f0b78dbf0370e..a677a2e640bf76701069971d0a64cb7d54b23554 100644
--- a/dht/closest_nodes.go
+++ b/dht/closest_nodes.go
@@ -23,7 +23,7 @@ func (me *nodeMaxHeap) Push(val interface{}) {
 	me.IDs = append(me.IDs, val.(string))
 }
 func (me nodeMaxHeap) Swap(i, j int) {
-	me.IDs[i], me.IDs[j] = me.IDs[i], me.IDs[j]
+	me.IDs[i], me.IDs[j] = me.IDs[j], me.IDs[i]
 }
 
 type closestNodesSelector struct {
diff --git a/tracker/udp/udp_tracker.go b/tracker/udp/udp_tracker.go
index c544aad4b07e9f0494792e93332e56cae7418f94..4ca75da7c3215c67d318777e69075dc0af1e05c1 100644
--- a/tracker/udp/udp_tracker.go
+++ b/tracker/udp/udp_tracker.go
@@ -124,7 +124,6 @@ 			IP:   p.IP[:],
 			Port: int(p.Port),
 		})
 	}
-	return
 }
 
 func (c *client) write(h *RequestHeader, body interface{}) (err error) {