diff --git a/atalk/nbp/nbp.go b/atalk/nbp/nbp.go
index 20acd90..423533d 100644
--- a/atalk/nbp/nbp.go
+++ b/atalk/nbp/nbp.go
@@ -36,12 +36,18 @@ const (
 )
 
 func (f Function) String() string {
-	return map[Function]string{
-		FunctionBrRq:      "BrRq",
-		FunctionLkUp:      "LkUp",
-		FunctionLkUpReply: "LkUp-Reply",
-		FunctionFwdReq:    "FwdReq",
-	}[f]
+	switch f {
+	case FunctionBrRq:
+		return "BrRq"
+	case FunctionLkUp:
+		return "LkUp"
+	case FunctionLkUpReply:
+		return "LkUp-Reply"
+	case FunctionFwdReq:
+		return "FwdReq"
+	default:
+		return "unknown"
+	}
 }
 
 // Packet represents an NBP packet.
diff --git a/router/peer.go b/router/peer.go
index 0016ade..cf50e9c 100644
--- a/router/peer.go
+++ b/router/peer.go
@@ -48,13 +48,20 @@ const (
 )
 
 func (rs receiverState) String() string {
-	return map[receiverState]string{
-		rsUnconnected:      "unconnected",
-		rsConnected:        "connected",
-		rsWaitForOpenRsp:   "waiting for Open-Rsp",
-		rsWaitForRIRsp:     "waiting for RI-Rsp",
-		rsWaitForTickleAck: "waiting for Tickle-Ack",
-	}[rs]
+	switch rs {
+	case rsUnconnected:
+		return "unconnected"
+	case rsConnected:
+		return "connected"
+	case rsWaitForOpenRsp:
+		return "waiting for Open-Rsp"
+	case rsWaitForRIRsp:
+		return "waiting for RI-Rsp"
+	case rsWaitForTickleAck:
+		return "waiting for Tickle-Ack"
+	default:
+		return "unknown"
+	}
 }
 
 type senderState int
@@ -68,13 +75,20 @@ const (
 )
 
 func (ss senderState) String() string {
-	return map[senderState]string{
-		ssUnconnected:     "unconnected",
-		ssConnected:       "connected",
-		ssWaitForRIRspAck: "waiting for RI-Ack for RI-Rsp",
-		ssWaitForRIUpdAck: "waiting for RI-Ack for RI-Upd",
-		ssWaitForRDAck:    "waiting for RI-Ack for RD",
-	}[ss]
+	switch ss {
+	case ssUnconnected:
+		return "unconnected"
+	case ssConnected:
+		return "connected"
+	case ssWaitForRIRspAck:
+		return "waiting for RI-Ack for RI-Rsp"
+	case ssWaitForRIUpdAck:
+		return "waiting for RI-Ack for RI-Upd"
+	case ssWaitForRDAck:
+		return "waiting for RI-Ack for RD"
+	default:
+		return "unknown"
+	}
 }
 
 type Peer struct {