diff --git a/.golangci.yml b/.golangci.yml
index 46579a63..3f2383c0 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -32,6 +32,12 @@ linters-settings:
 linters:
   enable-all: true
   disable:
+    # Allow dynamic errors.
+    - goerr113
+
+    # We want to allow short variable names.
+    - varnamelen
+
     # Init functions are used by loggers throughout the codebase.
     - gochecknoinits
 
@@ -46,6 +52,11 @@ linters:
     # instances are created.
     - exhaustruct
 
+    # Disable gofumpt as it has weird behavior regarding formatting multiple
+    # lines for a function which is in conflict with our contribution
+    # guidelines. See https://github.com/mvdan/gofumpt/issues/235.
+    - gofumpt
+
     # Deprecated linters. See https://golangci-lint.run/usage/linters/.
     - interfacer
     - golint
diff --git a/gbn/gbn_client.go b/gbn/gbn_client.go
index 7061194b..cdfa86f6 100644
--- a/gbn/gbn_client.go
+++ b/gbn/gbn_client.go
@@ -96,7 +96,10 @@ func (g *GoBackNConn) clientHandshake() error {
 		}
 	}()
 
-	var resp Message
+	var (
+		resp    Message
+		respSYN *PacketSYN
+	)
 handshake:
 	for {
 		// start Handshake
@@ -148,8 +151,10 @@ handshake:
 
 			g.log.Debugf("Got %T", resp)
 
-			switch resp.(type) {
+			switch r := resp.(type) {
 			case *PacketSYN:
+				respSYN = r
+
 				break handshake
 			default:
 			}
@@ -162,7 +167,7 @@ handshake:
 
 	g.log.Debugf("Got SYN")
 
-	if resp.(*PacketSYN).N != g.cfg.n {
+	if respSYN.N != g.cfg.n {
 		return io.EOF
 	}
 
diff --git a/gbn/gbn_conn.go b/gbn/gbn_conn.go
index f76c1ec4..1f8d974a 100644
--- a/gbn/gbn_conn.go
+++ b/gbn/gbn_conn.go
@@ -67,7 +67,7 @@ type GoBackNConn struct {
 	// remoteClosed is closed if the remote party initiated the FIN sequence.
 	remoteClosed chan struct{}
 
-	ctx    context.Context
+	ctx    context.Context //nolint:containedctx
 	cancel func()
 
 	// quit is used to stop the normal operations of the connection.
diff --git a/mailbox/server.go b/mailbox/server.go
index a0a820b0..f810fbc8 100644
--- a/mailbox/server.go
+++ b/mailbox/server.go
@@ -26,7 +26,7 @@ type Server struct {
 
 	sid [64]byte
 
-	ctx context.Context
+	ctx context.Context //nolint:containedctx
 
 	quit   chan struct{}
 	cancel func()