diff --git a/Changelog.md b/Changelog.md
index 8c715ea4100e82c75c949a3b65b9a14ac2c3ed2e..2fcc640ec893d53814f9573fb514116ff0e48dd5 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -4,6 +4,11 @@ This Changelog records major changes between versions.
 
 Not all changes are recorded. Please check git log for details.
 
+## Version 2.1.1
+
+- Add a set of Dockerfile contributed by the community
+- Include DNS.SB's resolver in example configuration
+
 ## Version 2.1.0
 
 - Add `local_addr` configuration for doh-server (#39)
diff --git a/doh-client/version.go b/doh-client/version.go
index dcdf3c80f3049459878460f006c21caf6f015894..1c6b7bfdd7b7d848a41c3a34d7cdd0323ac5bbd5 100644
--- a/doh-client/version.go
+++ b/doh-client/version.go
@@ -24,6 +24,6 @@
 package main
 
 const (
-	VERSION    = "2.1.0"
+	VERSION    = "2.1.1"
 	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
 )
diff --git a/doh-server/version.go b/doh-server/version.go
index dcdf3c80f3049459878460f006c21caf6f015894..1c6b7bfdd7b7d848a41c3a34d7cdd0323ac5bbd5 100644
--- a/doh-server/version.go
+++ b/doh-server/version.go
@@ -24,6 +24,6 @@
 package main
 
 const (
-	VERSION    = "2.1.0"
+	VERSION    = "2.1.1"
 	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
 )
diff --git a/go.mod b/go.mod
index 6313e171d263cc54fd36a1987233c4740ee25a23..d9fb1b4c47a646c6e52b12d589207f67b7a9ef10 100644
--- a/go.mod
+++ b/go.mod
@@ -6,9 +6,7 @@ require (
 	github.com/BurntSushi/toml v0.3.1
 	github.com/gorilla/handlers v1.4.0
 	github.com/miekg/dns v1.1.14
-	golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 // indirect
-	golang.org/x/net v0.0.0-20190613194153-d28f0bde5980
-	golang.org/x/sys v0.0.0-20190614084037-d442b75600c5 // indirect
-	golang.org/x/text v0.3.2 // indirect
-	golang.org/x/tools v0.0.0-20190613204242-ed0dc450797f // indirect
+	golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4 // indirect
+	golang.org/x/net v0.0.0-20190620200207-3b0461eec859
+	golang.org/x/sys v0.0.0-20190621203818-d432491b9138 // indirect
 )
diff --git a/go.sum b/go.sum
index 970030fb7d0d53a7505184f8571cb5c788bb427b..b59d0d24dee7fe5a8ba6aa0ddd6d82fce250a44e 100644
--- a/go.sum
+++ b/go.sum
@@ -2,55 +2,17 @@ github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/gorilla/handlers v1.4.0 h1:XulKRWSQK5uChr4pEgSE4Tc/OcmnU9GJuSwdog/tZsA=
 github.com/gorilla/handlers v1.4.0/go.mod h1:Qkdc/uu4tH4g6mTK6auzZ766c4CA0Ng8+o/OAirnOIQ=
-github.com/miekg/dns v1.1.4 h1:rCMZsU2ScVSYcAsOXgmC6+AKOK+6pmQTOcw03nfwYV0=
-github.com/miekg/dns v1.1.4/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-github.com/miekg/dns v1.1.6 h1:jVwb4GDwD65q/gtItR/lIZHjNH93QfeGxZUkzJcW9mc=
-github.com/miekg/dns v1.1.6/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-github.com/miekg/dns v1.1.9 h1:OIdC9wT96RzuZMf2PfKRhFgsStHUUBZLM/lo1LqiM9E=
-github.com/miekg/dns v1.1.9/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-github.com/miekg/dns v1.1.12 h1:WMhc1ik4LNkTg8U9l3hI1LvxKmIL+f1+WV/SZtCbDDA=
-github.com/miekg/dns v1.1.12/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/miekg/dns v1.1.14 h1:wkQWn9wIp4mZbwW8XV6Km6owkvRPbOiV004ZM2CkGvA=
 github.com/miekg/dns v1.1.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a h1:YX8ljsm6wXlHZO+aRz9Exqr0evNhKRNe5K/gi+zKh4U=
-golang.org/x/crypto v0.0.0-20190313024323-a1f597ede03a/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f h1:R423Cnkcp5JABoeemiGEPlt9tHXFfw5kvc0yqlxRPWo=
-golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
-golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95 h1:fY7Dsw114eJN4boqzVSbpVHO6rTdhq6/GnXeu+PKnzU=
-golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4 h1:ydJNl0ENAG67pFbB+9tfhiL2pYqLhfoaZFw/cjLhY4A=
+golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190509222800-a4d6f7feada5 h1:6M3SDHlHHDCx2PcQw3S4KsR170vGqDhJDOmpVd4Hjak=
-golang.org/x/net v0.0.0-20190509222800-a4d6f7feada5/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190522155817-f3200d17e092 h1:4QSRKanuywn15aTZvI/mIDEgPQpswuFndXpOj3rKEco=
-golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
-golang.org/x/net v0.0.0-20190613194153-d28f0bde5980 h1:dfGZHvZk057jK2MCeWus/TowKpJ8y4AmooUzdBSR9GU=
-golang.org/x/net v0.0.0-20190613194153-d28f0bde5980/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 h1:bjcUS9ztw9kFmmIxJInhon/0Is3p+EHBKNgquIzo1OI=
-golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859 h1:R/3boaszxrf1GEUWTVDzSKVwLmSJpwZ1yqXm8j0v2QI=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190308023053-584f3b12f43e h1:K7CV15oJ823+HLXQ+M7MSMrUg8LjfqY7O3naO+8Pp/I=
-golang.org/x/sys v0.0.0-20190308023053-584f3b12f43e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190312061237-fead79001313 h1:pczuHS43Cp2ktBEEmLwScxgjWsBSzdaQiKzUyf3DTTc=
-golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190509141414-a5b02f93d862 h1:rM0ROo5vb9AdYJi1110yjWGMej9ITfKddS89P3Fkhug=
-golang.org/x/sys v0.0.0-20190509141414-a5b02f93d862/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190526052359-791d8a0f4d09 h1:IlD35wZE03o2qJy2o37WIskL33b7PT6cHdGnE8bieZs=
-golang.org/x/sys v0.0.0-20190526052359-791d8a0f4d09/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190614084037-d442b75600c5 h1:tQrtnaPeNyfkuD2UMixVD6lAa7WngkIFvtWcdzNeq80=
-golang.org/x/sys v0.0.0-20190614084037-d442b75600c5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190621203818-d432491b9138 h1:t8BZD9RDjkm9/h7yYN6kE8oaeov5r9aztkB7zKA5Tkg=
+golang.org/x/sys v0.0.0-20190621203818-d432491b9138/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
-golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20190513172155-8696927a2839/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
-golang.org/x/tools v0.0.0-20190525145741-7be61e1b0e51/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
-golang.org/x/tools v0.0.0-20190613204242-ed0dc450797f/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=