diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2314bc48..d23af19e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -83,7 +83,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go: ["1.20", "1.21"]
+        go: ["1.21"]
     steps:
       - uses: actions/checkout@v3
         with:
diff --git a/.golangci.yml b/.golangci.yml
index 97ca3786..48ea8cab 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -2,15 +2,8 @@ run:
   timeout: 5m
 linters:
   enable:
-    - vet
-    - vetshadow
     - typecheck
-    - deadcode
     - gocyclo
-    - golint
-    - varcheck
-    - structcheck
-    - maligned
     - ineffassign
 #    - gosec - complains about weak cryptographic primitive sha1 and TLS InsecureSkipVerify set true in getTransport
     - misspell
@@ -19,5 +12,4 @@ linters:
 #    - goconst
     - unconvert
     - errcheck
-    - interfacer
 #    - testify - not available in golangci-lint
diff --git a/fclient/client.go b/fclient/client.go
index 36c96579..97f93660 100644
--- a/fclient/client.go
+++ b/fclient/client.go
@@ -21,7 +21,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
@@ -350,7 +350,7 @@ func (fc *Client) LookupUserInfo(
 	}
 	if response.StatusCode < 200 || response.StatusCode >= 300 {
 		var errorOutput []byte
-		errorOutput, err = ioutil.ReadAll(response.Body)
+		errorOutput, err = io.ReadAll(response.Body)
 		if err != nil {
 			return
 		}
@@ -525,7 +525,7 @@ func (fc *Client) DoRequestAndParseResponse(
 	if response.StatusCode/100 != 2 { // not 2xx
 		// Adapted from https://github.com/matrix-org/gomatrix/blob/master/client.go
 		var contents []byte
-		contents, err = ioutil.ReadAll(response.Body)
+		contents, err = io.ReadAll(response.Body)
 		if err != nil {
 			return err
 		}
diff --git a/fclient/federationclient_test.go b/fclient/federationclient_test.go
index f77c2480..e2ec65a5 100644
--- a/fclient/federationclient_test.go
+++ b/fclient/federationclient_test.go
@@ -5,7 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"reflect"
 	"strings"
@@ -63,7 +63,7 @@ func TestSendJoinFallback(t *testing.T) {
 					if strings.HasPrefix(req.URL.Path, "/_matrix/federation/v2/send_join") {
 						return &http.Response{
 							StatusCode: 404,
-							Body:       ioutil.NopCloser(strings.NewReader("404 not found")),
+							Body:       io.NopCloser(strings.NewReader("404 not found")),
 						}, nil
 					}
 					if !strings.HasPrefix(req.URL.Path, "/_matrix/federation/v1/send_join") {
@@ -72,7 +72,7 @@ func TestSendJoinFallback(t *testing.T) {
 					t.Logf("Sending response: %s", string(v1ResBytes))
 					return &http.Response{
 						StatusCode: 200,
-						Body:       ioutil.NopCloser(bytes.NewReader(v1ResBytes)),
+						Body:       io.NopCloser(bytes.NewReader(v1ResBytes)),
 					}, nil
 				},
 			},
@@ -126,12 +126,12 @@ func TestSendJoinJSON(t *testing.T) {
 						t.Logf("Sending response: %s", string(respSendJoinResponseJSON))
 						return &http.Response{
 							StatusCode: 200,
-							Body:       ioutil.NopCloser(bytes.NewReader(respSendJoinResponseJSON)),
+							Body:       io.NopCloser(bytes.NewReader(respSendJoinResponseJSON)),
 						}, nil
 					}
 					return &http.Response{
 						StatusCode: 404,
-						Body:       ioutil.NopCloser(strings.NewReader("404 not found")),
+						Body:       io.NopCloser(strings.NewReader("404 not found")),
 					}, nil
 				},
 			},
@@ -185,12 +185,12 @@ func TestSendTransactionToRelay(t *testing.T) {
 					if strings.HasPrefix(req.URL.Path, "/_matrix/federation/v1/send_relay") {
 						return &http.Response{
 							StatusCode: 200,
-							Body:       ioutil.NopCloser(bytes.NewReader(respSendResponseJSON)),
+							Body:       io.NopCloser(bytes.NewReader(respSendResponseJSON)),
 						}, nil
 					}
 					return &http.Response{
 						StatusCode: 404,
-						Body:       ioutil.NopCloser(strings.NewReader("404 not found")),
+						Body:       io.NopCloser(strings.NewReader("404 not found")),
 					}, nil
 				},
 			},
@@ -232,12 +232,12 @@ func TestSendTransactionToRelayReportsFailure(t *testing.T) {
 					if strings.HasPrefix(req.URL.Path, "/_matrix/federation/v1/send_relay") {
 						return &http.Response{
 							StatusCode: 400,
-							Body:       ioutil.NopCloser(bytes.NewReader(respSendResponseJSON)),
+							Body:       io.NopCloser(bytes.NewReader(respSendResponseJSON)),
 						}, nil
 					}
 					return &http.Response{
 						StatusCode: 404,
-						Body:       ioutil.NopCloser(strings.NewReader("404 not found")),
+						Body:       io.NopCloser(strings.NewReader("404 not found")),
 					}, nil
 				},
 			},
diff --git a/fclient/request.go b/fclient/request.go
index 188a47bb..0d2622ef 100644
--- a/fclient/request.go
+++ b/fclient/request.go
@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"mime"
 	"net/http"
 	"strings"
@@ -183,7 +182,7 @@ func isSafeInHTTPQuotedString(text string) bool { // nolint: gocyclo
 			continue
 		case 0x5D <= c && c <= 0x7E:
 			continue
-		case 0x80 <= c && c <= 0xFF:
+		case 0x80 <= c:
 			continue
 		default:
 			return false
@@ -274,7 +273,7 @@ func readHTTPRequest(req *http.Request) (*FederationRequest, error) { // nolint:
 	result.fields.Method = req.Method
 	result.fields.RequestURI = req.URL.RequestURI()
 
-	content, err := ioutil.ReadAll(req.Body)
+	content, err := io.ReadAll(req.Body)
 	if err != nil {
 		return nil, err
 	}
diff --git a/spec/matrixerror.go b/spec/matrixerror.go
index a178c429..2088a7c1 100644
--- a/spec/matrixerror.go
+++ b/spec/matrixerror.go
@@ -15,6 +15,7 @@
 package spec
 
 import (
+	"errors"
 	"fmt"
 )
 
@@ -63,7 +64,7 @@ func (e MatrixError) Error() string {
 }
 
 func (e MatrixError) Unwrap() error {
-	return fmt.Errorf(e.Err)
+	return errors.New(e.Err)
 }
 
 // InternalServerError
@@ -231,7 +232,7 @@ func (e IncompatibleRoomVersionError) Error() string {
 }
 
 func (e IncompatibleRoomVersionError) Unwrap() error {
-	return fmt.Errorf(e.Err)
+	return errors.New(e.Err)
 }
 
 // IncompatibleRoomVersion is an error which is returned when the client
diff --git a/tokens/tokens_test.go b/tokens/tokens_test.go
index 7ffe9809..b8847411 100644
--- a/tokens/tokens_test.go
+++ b/tokens/tokens_test.go
@@ -61,17 +61,17 @@ func serializationTestError(err error) string {
 func TestSerialization(t *testing.T) {
 	fakeToken, err := GenerateLoginToken(validTokenOp)
 	if err != nil {
-		t.Errorf(serializationTestError(err))
+		t.Errorf("%s", serializationTestError(err))
 	}
 
 	fakeMacaroon, err := deSerializeMacaroon(fakeToken)
 	if err != nil {
-		t.Errorf(serializationTestError(err))
+		t.Errorf("%s", serializationTestError(err))
 	}
 
 	sameFakeToken, err := serializeMacaroon(fakeMacaroon)
 	if err != nil {
-		t.Errorf(serializationTestError(err))
+		t.Errorf("%s", serializationTestError(err))
 	}
 
 	if sameFakeToken != fakeToken {