diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1f3a6eb
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+# IDE files
+.idea/
+*.iml
diff --git a/.travis.yml b/.travis.yml
index 1f0b188..9b5d2c1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,8 @@
 language: go
 
 go:
-  - 1.13.x
-  - 1.12.x
-  - 1.11.x
+  - 1.16.x
+  - 1.15.x
   - master
 
 cache:
@@ -31,8 +30,8 @@ before_install:
    # pypy3 isn't packaged in ubuntu yet.
    - TEMPDIR=$(mktemp -d)
    - export PYPYVERSION=v7.1.1
-   - curl -L https://bitbucket.org/pypy/pypy/downloads/pypy2.7-${PYPYVERSION}-linux64.tar.bz2 --output $TEMPDIR/pypy2.tar.bz2
-   - curl -L https://bitbucket.org/pypy/pypy/downloads/pypy3.6-${PYPYVERSION}-linux64.tar.bz2 --output $TEMPDIR/pypy3.tar.bz2
+   - curl -L https://downloads.python.org/pypy/pypy2.7-${PYPYVERSION}-linux64.tar.bz2 --output $TEMPDIR/pypy2.tar.bz2
+   - curl -L https://downloads.python.org/pypy/pypy3.6-${PYPYVERSION}-linux64.tar.bz2 --output $TEMPDIR/pypy3.tar.bz2
    - tar xf $TEMPDIR/pypy2.tar.bz2 -C $TEMPDIR
    - tar xf $TEMPDIR/pypy3.tar.bz2 -C $TEMPDIR
    - sudo ln -s $TEMPDIR/pypy2.7-$PYPYVERSION-linux64/bin/pypy  /usr/local/bin/pypy
diff --git a/_examples/iface/iface.go b/_examples/iface/iface.go
index 0ec1d77..56d9863 100644
--- a/_examples/iface/iface.go
+++ b/_examples/iface/iface.go
@@ -36,7 +36,7 @@ func IfaceString(str interface{}) {
 	cpkg.Printf("iface as string: %v\n", str)
 }
 
-//gopy:interface=handle
+// gopy:interface=handle
 // this magic directive says, treat the interface arg as a handle
 func IfaceHandle(ifc interface{}) {
 	cpkg.Printf("iface as handle: %v\n", ifc)
diff --git a/_examples/rename/rename.go b/_examples/rename/rename.go
index 0dc7068..8342b9b 100644
--- a/_examples/rename/rename.go
+++ b/_examples/rename/rename.go
@@ -5,7 +5,7 @@
 // package rename tests changing the names of methods and functions
 package rename
 
-//gopy:name say_hi
+// gopy:name say_hi
 func SayHi() string {
 	return "hi"
 }
@@ -13,7 +13,7 @@ func SayHi() string {
 type MyStruct struct {
 }
 
-//gopy:name say_something
+// gopy:name say_something
 func (s *MyStruct) SaySomething() (something string) {
 	return "something"
 }
diff --git a/appveyor.yml b/appveyor.yml
index 9697f17..acded50 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,3 +1,5 @@
+image: Previous Visual Studio 2019
+
 build: off
 
 clone_folder: c:\gopath\src\github.com\go-python\gopy
@@ -11,15 +13,16 @@ branches:
     - master
 
 environment:
-  GOPATH: c:\gopath
+  GOPATH: C:\gopath
+  GOROOT: C:\go115
   GOPY_APPVEYOR_CI: '1'
   GOTRACEBACK: 'crash'
   #CPYTHON2DIR: "C:\\Python27-x64"
   CPYTHON3DIR: "C:\\Python37-x64"
   #PATH: '%GOPATH%\bin;%CPYTHON2DIR%;%CPYTHON2DIR%\\Scripts;%CPYTHON3DIR%;%CPYTHON3DIR%\\Scripts;C:\msys64\mingw64\bin;C:\msys64\usr\bin\;%PATH%'
-  PATH: '%GOPATH%\bin;%CPYTHON3DIR%;%CPYTHON3DIR%\\Scripts;C:\msys64\mingw64\bin;C:\msys64\usr\bin\;%PATH%'
+  PATH: '%GOPATH%\bin;%GOROOT%\bin;%CPYTHON3DIR%;%CPYTHON3DIR%\\Scripts;C:\msys64\mingw64\bin;C:\msys64\usr\bin\;%PATH%'
 
-stack: go 1.13
+stack: go 1.15
 
 build_script:
   - python --version
@@ -31,6 +34,8 @@ build_script:
   - "%CPYTHON3DIR%\\python -m pip install cffi"
     #- "%CPYTHON2DIR%\\python -m pip install pybindgen"
   - "%CPYTHON3DIR%\\python -m pip install pybindgen"
+  - go version
+  - go env
   - go get -v -t ./...
 
 test_script:
diff --git a/bind/utils_test.go b/bind/utils_test.go
index 6b2841e..8d230c2 100644
--- a/bind/utils_test.go
+++ b/bind/utils_test.go
@@ -75,7 +75,7 @@ func TestPythonConfig(t *testing.T) {
 
 	for _, tc := range []struct {
 		vm   string
-		want pyconfig
+		want PyConfig
 	}{
 		{
 			vm: "python2",
diff --git a/go.mod b/go.mod
index 914e8fa..8897e03 100644
--- a/go.mod
+++ b/go.mod
@@ -6,5 +6,5 @@ require (
 	github.com/gonuts/commander v0.1.0
 	github.com/gonuts/flag v0.1.0
 	github.com/pkg/errors v0.9.1
-	golang.org/x/tools v0.0.0-20201123232213-4aa1a224cdb5
+	golang.org/x/tools v0.1.0
 )
diff --git a/go.sum b/go.sum
index 973dc34..a7e268a 100644
--- a/go.sum
+++ b/go.sum
@@ -4,26 +4,33 @@ github.com/gonuts/flag v0.1.0 h1:fqMv/MZ+oNGu0i9gp0/IQ/ZaPIDoAZBOBaJoV7viCWM=
 github.com/gonuts/flag v0.1.0/go.mod h1:ZTmTGtrSPejTo/SRNhCqwLTmiAgyBdCkLYhHrAoBdz4=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/yuin/goldmark v1.2.1 h1:ruQGxdhGHe7FWOJPT0mKs5+pD2Xs1Bm/kdGlHO04FmM=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 h1:psW17arqaxU48Z5kZ0CQnkZWQJsqcURM6tKiBApRjXI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974 h1:IX6qOQeG5uLjB/hjjwjedwfjND0hgjPMMyO1RoIXQNI=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 h1:SQFwaSi55rU7vdNs9Yr0Z324VNlrF+0wMqRXT4St8ck=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 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 v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 h1:myAQVi0cGEoqQVR5POX+8RR2mrocKqNN1hmeMqhX27k=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20201123232213-4aa1a224cdb5 h1:ylHD4UIwP+CofOZHT/selc5MjXJ3yZnEg2OfYkLaPXs=
-golang.org/x/tools v0.0.0-20201123232213-4aa1a224cdb5/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/tools v0.1.0 h1:po9/4sTYwZU9lPhi1tOrb4hCv3qrhiQ77LZfGa2OjwY=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
diff --git a/main_test.go b/main_test.go
index 5527bb9..e0cbc86 100644
--- a/main_test.go
+++ b/main_test.go
@@ -52,6 +52,11 @@ var (
 	testEnvironment = os.Environ()
 )
 
+func init() {
+	os.Setenv("GOFLAGS", "-mod=mod")
+	testEnvironment = append(testEnvironment, "GOFLAGS=-mod=mod")
+}
+
 func TestGovet(t *testing.T) {
 	cmd := exec.Command("go", "vet", "./...")
 	buf := new(bytes.Buffer)
diff --git a/version.go b/version.go
index 68127c0..e7f4164 100644
--- a/version.go
+++ b/version.go
@@ -3,8 +3,7 @@
 package main
 
 const (
-	Version = "v0.3.4"
-	GitCommit = "0d0bcab" // the commit JUST BEFORE the release
+	Version     = "v0.3.4"
+	GitCommit   = "0d0bcab"          // the commit JUST BEFORE the release
 	VersionDate = "2020-11-24 02:36" // UTC
 )
-