diff --git a/_js/build b/_js/build
index ba82a5e33..d89622ffb 100755
--- a/_js/build
+++ b/_js/build
@@ -10,5 +10,3 @@ export GO111MODULE=on # build in module-aware mode
 go run github.com/gopherjs/gopherjs build -o index.js || exit 1
 
 node testmain.js || exit 1
-
-go mod tidy # to remove unnecessary gopherjs lines from go.mod
diff --git a/_js/go.mod b/_js/go.mod
new file mode 100644
index 000000000..8b751bb00
--- /dev/null
+++ b/_js/go.mod
@@ -0,0 +1,12 @@
+module shjs
+
+go 1.11
+
+replace github.com/gopherjs/gopherjs => github.com/myitcv/gopherjs v0.0.0-20181206184521-f5b96be2a04c
+
+replace mvdan.cc/sh/v3 => ../
+
+require (
+	github.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e
+	mvdan.cc/sh/v3 v3.0.0-alpha0
+)
diff --git a/_js/go.sum b/_js/go.sum
new file mode 100644
index 000000000..598572f82
--- /dev/null
+++ b/_js/go.sum
@@ -0,0 +1,35 @@
+github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/myitcv/gopherjs v0.0.0-20181206184521-f5b96be2a04c h1:Anqc6H/ATT8okiZAOACY59ByomtxVvREjH3yx3xpAUU=
+github.com/myitcv/gopherjs v0.0.0-20181206184521-f5b96be2a04c/go.mod h1:+hbiahOXtaQVul9rb+ZH7/WXxTkkLWf/LtHzbqjjfPo=
+github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86 h1:D6paGObi5Wud7xg83MaEFyjxQB1W5bz5d0IFppr+ymk=
+github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86/go.mod h1:kHJEU3ofeGjhHklVoIGuVj85JJwZ6kWPaJwCIxgnFmo=
+github.com/neelance/sourcemap v0.0.0-20151028013722-8c68805598ab h1:eFXv9Nu1lGbrNbj619aWwZfVF5HBrm9Plte8aNptuTI=
+github.com/neelance/sourcemap v0.0.0-20151028013722-8c68805598ab/go.mod h1:Qr6/a/Q4r9LP1IltGz7tA7iOK1WonHEYhu1HRBA7ZiM=
+github.com/rogpeppe/go-internal v1.0.1-alpha.1 h1:NGPDe06RaK5iQFZkqFMNb986UARfoHc9FLyWI7b6+aQ=
+github.com/rogpeppe/go-internal v1.0.1-alpha.1/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
+github.com/shurcooL/go v0.0.0-20180423040247-9e1955d9fb6e/go.mod h1:TDJrrUr11Vxrven61rcy3hJMUqaf/CLWYhHNPmT14Lk=
+github.com/shurcooL/httpfs v0.0.0-20171119174359-809beceb2371 h1:SWV2fHctRpRrp49VXJ6UZja7gU9QLHwRpIPBN89SKEo=
+github.com/shurcooL/httpfs v0.0.0-20171119174359-809beceb2371/go.mod h1:ZY1cvUeJuFPAdZ/B6v7RHavJWZn2YPVFQ1OSXhCGOkg=
+github.com/shurcooL/vfsgen v0.0.0-20180915214035-33ae1944be3f/go.mod h1:TrYk7fJVaAttu97ZZKrO9UbRa8izdowaMIZcxYMbVaw=
+github.com/spf13/cobra v0.0.3 h1:ZlrZ4XsMRm04Fr5pSFxBgfND2EBVa1nLpiy1stUsX/8=
+github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
+github.com/spf13/pflag v1.0.1 h1:aCvUg6QPl3ibpQUxyLkrEkCHtPqYJL4x9AuhqVqFis4=
+github.com/spf13/pflag v1.0.1/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+golang.org/x/crypto v0.0.0-20180807104621-f027049dab0a h1:PulT0Y50PcfTWomfsD39bSQyVrjjWdIuJKfyR4nOCJw=
+golang.org/x/crypto v0.0.0-20180807104621-f027049dab0a/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20181106171534-e4dc69e5b2fd h1:VtIkGDhk0ph3t+THbvXHfMZ8QHgsBO39Nh52+74pq7w=
+golang.org/x/crypto v0.0.0-20181106171534-e4dc69e5b2fd/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180807162357-acbc56fc7007 h1:UnHxDq9ldm4vol94wlSWDF3SU4IyC8IWVWtg266CzoY=
+golang.org/x/sys v0.0.0-20180807162357-acbc56fc7007/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8 h1:YoY1wS6JYVRpIfFngRf2HHo9R9dAne3xbkGOQ5rJXjU=
+golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/tools v0.0.0-20180803180156-3c07937fe18c h1:Z6Xcg33osoOLCiz/EFPHedK6zJ9nl1KK4WH/LlykMxs=
+golang.org/x/tools v0.0.0-20180803180156-3c07937fe18c/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
diff --git a/go.mod b/go.mod
index 8bcc2b4cd..6aacfc2f6 100644
--- a/go.mod
+++ b/go.mod
@@ -8,5 +8,3 @@ require (
 	golang.org/x/sync v0.0.0-20181108010431-42b317875d0f
 	golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8 // indirect
 )
-
-replace github.com/gopherjs/gopherjs => github.com/myitcv/gopherjs v0.0.0-20181206184521-f5b96be2a04c