diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4bf6a95..0c7a586 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Edit current URL with <kbd>e</kbd> (#87)
 - If `emoji_favicons` is enabled, new bookmarks will have the domain's favicon prepended (#69, #90)
 - The `BROWSER` env var is now also checked when opening web links on Unix (#93)
+- Allow specifying a client certificate
 
 ### Changed
 - Disabling the `color` config setting also disables ANSI colors in pages (#79, #86)
diff --git a/client/client.go b/client/client.go
index 4bc1557..f5d4b99 100644
--- a/client/client.go
+++ b/client/client.go
@@ -2,23 +2,74 @@
 package client
 
 import (
+	"io/ioutil"
 	"net"
 	"net/url"
 
 	"github.com/makeworld-the-better-one/go-gemini"
+	"github.com/mitchellh/go-homedir"
+	"github.com/spf13/viper"
 )
 
+var certCache = make(map[string][][]byte)
+
+func clientCert(host string) ([]byte, []byte) {
+	if cert := certCache[host]; cert != nil {
+		return cert[0], cert[1]
+	}
+
+	// Expand paths staring with ~/
+	certPath, err := homedir.Expand(viper.GetString("auth.certs." + host))
+	if err != nil {
+		certPath = viper.GetString("auth.certs." + host)
+	}
+	keyPath, err := homedir.Expand(viper.GetString("auth.keys." + host))
+	if err != nil {
+		keyPath = viper.GetString("auth.keys." + host)
+	}
+	if certPath == "" && keyPath == "" {
+		certCache[host] = [][]byte{nil, nil}
+		return nil, nil
+	}
+
+	cert, err := ioutil.ReadFile(certPath)
+	if err != nil {
+		certCache[host] = [][]byte{nil, nil}
+		return nil, nil
+	}
+	key, err := ioutil.ReadFile(keyPath)
+	if err != nil {
+		certCache[host] = [][]byte{nil, nil}
+		return nil, nil
+	}
+
+	certCache[host] = [][]byte{cert, key}
+	return cert, key
+}
+
+// HasClientCert returns whether or not a client certificate exists for a host.
+func HasClientCert(host string) bool {
+	cert, _ := clientCert(host)
+	return cert != nil
+}
+
 // Fetch returns response data and an error.
 // The error text is human friendly and should be displayed.
 func Fetch(u string) (*gemini.Response, error) {
+	parsed, _ := url.Parse(u)
+	cert, key := clientCert(parsed.Host)
 
-	res, err := gemini.Fetch(u)
+	var res *gemini.Response
+	var err error
+	if cert != nil {
+		res, err = gemini.FetchWithCert(u, cert, key)
+	} else {
+		res, err = gemini.Fetch(u)
+	}
 	if err != nil {
 		return nil, err
 	}
 
-	parsed, _ := url.Parse(u)
-
 	ok := handleTofu(parsed.Hostname(), parsed.Port(), res.Cert)
 	if !ok {
 		return res, ErrTofu
@@ -29,7 +80,16 @@ func Fetch(u string) (*gemini.Response, error) {
 
 // FetchWithProxy is the same as Fetch, but uses a proxy.
 func FetchWithProxy(proxyHostname, proxyPort, u string) (*gemini.Response, error) {
-	res, err := gemini.FetchWithHost(net.JoinHostPort(proxyHostname, proxyPort), u)
+	parsed, _ := url.Parse(u)
+	cert, key := clientCert(parsed.Host)
+
+	var res *gemini.Response
+	var err error
+	if cert != nil {
+		res, err = gemini.FetchWithHostAndCert(net.JoinHostPort(proxyHostname, proxyPort), u, cert, key)
+	} else {
+		res, err = gemini.FetchWithHost(net.JoinHostPort(proxyHostname, proxyPort), u)
+	}
 	if err != nil {
 		return nil, err
 	}
diff --git a/config/default.go b/config/default.go
index 11cc1ef..cac1ad8 100644
--- a/config/default.go
+++ b/config/default.go
@@ -59,6 +59,18 @@ page_max_time = 10
 emoji_favicons = false
 
 
+[auth]
+# Authentication settings
+
+[auth.certs]
+# Client certificates
+# "example.com" = "mycert.crt"
+
+[auth.keys]
+# Client certificate keys
+# "example.com" = "mycert.key"
+
+
 [keybindings]
 # In the future there will be more settings here.
 
diff --git a/default-config.toml b/default-config.toml
index 4242bb1..4256091 100644
--- a/default-config.toml
+++ b/default-config.toml
@@ -56,6 +56,18 @@ page_max_time = 10
 emoji_favicons = false
 
 
+[auth]
+# Authentication settings
+
+[auth.certs]
+# Client certificates
+# "example.com" = "mycert.crt"
+
+[auth.keys]
+# Client certificate keys
+# "example.com" = "mycert.key"
+
+
 [keybindings]
 # In the future there will be more settings here.
 
diff --git a/go.mod b/go.mod
index a94d5e1..61549ab 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
 	github.com/gdamore/tcell v1.3.1-0.20200608133353-cb1e5d6fa606
 	github.com/google/go-cmp v0.5.0 // indirect
-	github.com/makeworld-the-better-one/go-gemini v0.8.4
+	github.com/makeworld-the-better-one/go-gemini v0.9.0
 	github.com/makeworld-the-better-one/go-isemoji v1.1.0
 	github.com/makeworld-the-better-one/progressbar/v3 v3.3.5-0.20200710151429-125743e22b4f
 	github.com/mitchellh/go-homedir v1.1.0
diff --git a/go.sum b/go.sum
index 8639569..2ce1789 100644
--- a/go.sum
+++ b/go.sum
@@ -125,8 +125,8 @@ github.com/lucasb-eyer/go-colorful v1.0.3 h1:QIbQXiugsb+q10B+MI+7DI1oQLdmnep86tW
 github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/magiconair/properties v1.8.1 h1:ZC2Vc7/ZFkGmsVC9KvOjumD+G5lXy2RtTKyzRKO2BQ4=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
-github.com/makeworld-the-better-one/go-gemini v0.8.4 h1:ntsQ9HnlJCmC9PDqXp/f1SCALjBMwh69BbT4BhFRFaw=
-github.com/makeworld-the-better-one/go-gemini v0.8.4/go.mod h1:P7/FbZ+IEIbA/d+A0Y3w2GNgD8SA2AcNv7aDGJbaWG4=
+github.com/makeworld-the-better-one/go-gemini v0.9.0 h1:Iz4ywRDrfsyoR8xZOkSKGXXftMR2spIV6ibVuhrKvSw=
+github.com/makeworld-the-better-one/go-gemini v0.9.0/go.mod h1:P7/FbZ+IEIbA/d+A0Y3w2GNgD8SA2AcNv7aDGJbaWG4=
 github.com/makeworld-the-better-one/go-isemoji v1.1.0 h1:wZBHOKB5zAIgaU2vaWnXFDDhatebB8TySrNVxjVV84g=
 github.com/makeworld-the-better-one/go-isemoji v1.1.0/go.mod h1:FBjkPl9rr0G4vlZCc+Mr+QcnOfGCTbGWYW8/1sp06I0=
 github.com/makeworld-the-better-one/progressbar/v3 v3.3.5-0.20200710151429-125743e22b4f h1:YEUlTs5gb35UlBLTgqrub9axWTYB3d7/8TxrkJDZpRI=