diff --git a/.gitmodules b/.gitmodules
deleted file mode 100644
index e92e0e6..0000000
--- a/.gitmodules
+++ /dev/null
@@ -1,30 +0,0 @@
-[submodule "vendor/github.com/stretchr/testify"]
-	path = vendor/github.com/stretchr/testify
-	url = https://github.com/stretchr/testify
-[submodule "vendor/golang.org/x/crypto"]
-	path = vendor/golang.org/x/crypto
-	url = https://go.googlesource.com/crypto
-[submodule "vendor/github.com/btcsuite/btcrpcclient"]
-	path = vendor/github.com/btcsuite/btcrpcclient
-	url = https://github.com/btcsuite/btcrpcclient
-[submodule "vendor/github.com/btcsuite/btcd"]
-	path = vendor/github.com/btcsuite/btcd
-	url = https://github.com/btcsuite/btcd
-[submodule "vendor/github.com/btcsuite/btclog"]
-	path = vendor/github.com/btcsuite/btclog
-	url = https://github.com/btcsuite/btclog
-[submodule "vendor/github.com/btcsuite/seelog"]
-	path = vendor/github.com/btcsuite/seelog
-	url = https://github.com/btcsuite/seelog
-[submodule "vendor/github.com/btcsuite/btcutil"]
-	path = vendor/github.com/btcsuite/btcutil
-	url = https://github.com/btcsuite/btcutil
-[submodule "vendor/github.com/btcsuite/golangcrypto"]
-	path = vendor/github.com/btcsuite/golangcrypto
-	url = https://github.com/btcsuite/golangcrypto
-[submodule "vendor/github.com/btcsuite/go-socks"]
-	path = vendor/github.com/btcsuite/go-socks
-	url = https://github.com/btcsuite/go-socks
-[submodule "vendor/github.com/btcsuite/websocket"]
-	path = vendor/github.com/btcsuite/websocket
-	url = https://github.com/btcsuite/websocket
diff --git a/cmd/gots-dump/main.go b/cmd/gots-dump/main.go
index 60a84b4..0392215 100644
--- a/cmd/gots-dump/main.go
+++ b/cmd/gots-dump/main.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"log"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
 )
 
 func main() {
diff --git a/cmd/gots-stamp/main.go b/cmd/gots-stamp/main.go
index 674f11c..8c855a9 100644
--- a/cmd/gots-stamp/main.go
+++ b/cmd/gots-stamp/main.go
@@ -5,7 +5,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
 )
 
 const defaultCalendar = "https://alice.btc.calendar.opentimestamps.org"
diff --git a/cmd/gots-upgrade/main.go b/cmd/gots-upgrade/main.go
index 711a55a..ac673c4 100644
--- a/cmd/gots-upgrade/main.go
+++ b/cmd/gots-upgrade/main.go
@@ -6,7 +6,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
 )
 
 func main() {
diff --git a/cmd/gots-verify/main.go b/cmd/gots-verify/main.go
index e0a5aa5..bb12b29 100644
--- a/cmd/gots-verify/main.go
+++ b/cmd/gots-verify/main.go
@@ -5,9 +5,9 @@ import (
 	"fmt"
 	"log"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps/client"
-	"github.com/btcsuite/btcrpcclient"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps/client"
+	btcrpcclient "github.com/btcsuite/btcd/rpcclient"
 )
 
 func newBtcConn(host, user, pass string) (*btcrpcclient.Client, error) {
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..0a4eed6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,10 @@
+module github.com/blockchainsource/go-opentimestamps
+
+go 1.12
+
+require (
+	github.com/btcsuite/btcd v0.0.0-20191011231409-07282a6656b8
+	github.com/sirupsen/logrus v1.4.2
+	github.com/stretchr/testify v1.4.0
+	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..9477769
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,58 @@
+github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
+github.com/btcsuite/btcd v0.0.0-20191011231409-07282a6656b8 h1:VtBbiBsPRCedNPZELoycBnfoMcpSPnc5ktPh+ORniJw=
+github.com/btcsuite/btcd v0.0.0-20191011231409-07282a6656b8/go.mod h1:wVuoA8VJLEcwgqHBwHmzLRazpKxTv13Px/pDuV7OomQ=
+github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f h1:bAs4lUbRJpnnkd9VhRV3jjAVU7DJVjMaK+IsvSeZvFo=
+github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
+github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d h1:yJzD/yFppdVCf6ApMkVy8cUxV0XrxdP9rVf6D87/Mng=
+github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
+github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd h1:R/opQEbFEy9JGkIguV40SvRY1uliPX8ifOvi6ICsFCw=
+github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
+github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
+github.com/btcsuite/snappy-go v0.0.0-20151229074030-0bdef8d06723/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
+github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792 h1:R8vQdOQdZ9Y3SkEwmHoWBmX1DNXhXZqlTpq6s4tyJGc=
+github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtEyQwv5/p4Mg4C0fgbePVuGr935/5ddU9Z3TmDRY=
+github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
+github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
+github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/jrick/logrotate v1.0.0/go.mod h1:LNinyqDIJnpAur+b8yyulnQw/wDuN1+BYKlTRt3OuAQ=
+github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
+github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/opentimestamps/client/bitcoin.go b/opentimestamps/client/bitcoin.go
index 7323109..93ea56f 100644
--- a/opentimestamps/client/bitcoin.go
+++ b/opentimestamps/client/bitcoin.go
@@ -5,8 +5,8 @@ import (
 	"math"
 	"time"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
-	"github.com/btcsuite/btcrpcclient"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
+	btcrpcclient "github.com/btcsuite/btcd/rpcclient"
 )
 
 // A BitcoinAttestationVerifier uses a bitcoin RPC connection to verify bitcoin
diff --git a/opentimestamps/client/bitcoin_test.go b/opentimestamps/client/bitcoin_test.go
index 4c5d9fd..17db706 100644
--- a/opentimestamps/client/bitcoin_test.go
+++ b/opentimestamps/client/bitcoin_test.go
@@ -7,8 +7,8 @@ import (
 	"testing"
 	"time"
 
-	"github.com/BlockchainSource/go-opentimestamps/opentimestamps"
-	"github.com/btcsuite/btcrpcclient"
+	"github.com/blockchainsource/go-opentimestamps/opentimestamps"
+	btcrpcclient "github.com/btcsuite/btcd/rpcclient"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
diff --git a/opentimestamps/remote_calendar.go b/opentimestamps/remote_calendar.go
index d78dd89..7d5347a 100644
--- a/opentimestamps/remote_calendar.go
+++ b/opentimestamps/remote_calendar.go
@@ -9,7 +9,7 @@ import (
 	"net/http/httputil"
 	"strings"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 const userAgent = "go-opentimestamps"
diff --git a/opentimestamps/remote_calendar_test.go b/opentimestamps/remote_calendar_test.go
index 0dc7b8b..7f4126d 100644
--- a/opentimestamps/remote_calendar_test.go
+++ b/opentimestamps/remote_calendar_test.go
@@ -7,7 +7,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
diff --git a/vendor/github.com/btcsuite/btcd b/vendor/github.com/btcsuite/btcd
deleted file mode 160000
index 583684b..0000000
--- a/vendor/github.com/btcsuite/btcd
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 583684b21bfbde9b5fc4403916fd7c807feb0289
diff --git a/vendor/github.com/btcsuite/btclog b/vendor/github.com/btcsuite/btclog
deleted file mode 160000
index 73889fb..0000000
--- a/vendor/github.com/btcsuite/btclog
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 73889fb79bd687870312b6e40effcecffbd57d30
diff --git a/vendor/github.com/btcsuite/btcrpcclient b/vendor/github.com/btcsuite/btcrpcclient
deleted file mode 160000
index eef3939..0000000
--- a/vendor/github.com/btcsuite/btcrpcclient
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit eef39394b7eb639be140973f8f2dcc2020784f5f
diff --git a/vendor/github.com/btcsuite/btcutil b/vendor/github.com/btcsuite/btcutil
deleted file mode 160000
index 86346b5..0000000
--- a/vendor/github.com/btcsuite/btcutil
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 86346b5a958c0cf94186b87855469ae991be501c
diff --git a/vendor/github.com/btcsuite/go-socks b/vendor/github.com/btcsuite/go-socks
deleted file mode 160000
index 4720035..0000000
--- a/vendor/github.com/btcsuite/go-socks
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 4720035b7bfd2a9bb130b1c184f8bbe41b6f0d0f
diff --git a/vendor/github.com/btcsuite/golangcrypto b/vendor/github.com/btcsuite/golangcrypto
deleted file mode 160000
index 53f62d9..0000000
--- a/vendor/github.com/btcsuite/golangcrypto
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 53f62d9b43e87a6c56975cf862af7edf33a8d0df
diff --git a/vendor/github.com/btcsuite/seelog b/vendor/github.com/btcsuite/seelog
deleted file mode 160000
index 313961b..0000000
--- a/vendor/github.com/btcsuite/seelog
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 313961b101eb55f65ae0f03ddd4e322731763b6c
diff --git a/vendor/github.com/btcsuite/websocket b/vendor/github.com/btcsuite/websocket
deleted file mode 160000
index 31079b6..0000000
--- a/vendor/github.com/btcsuite/websocket
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 31079b6807923eb23992c421b114992b95131b55
diff --git a/vendor/github.com/stretchr/testify b/vendor/github.com/stretchr/testify
deleted file mode 160000
index 4d4bfba..0000000
--- a/vendor/github.com/stretchr/testify
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 4d4bfba8f1d1027c4fdbe371823030df51419987
diff --git a/vendor/golang.org/x/crypto b/vendor/golang.org/x/crypto
deleted file mode 160000
index 459e265..0000000
--- a/vendor/golang.org/x/crypto
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 459e26527287adbc2adcc5d0d49abff9a5f315a7