diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 5aa296ae61..33f6126ada 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -21,7 +21,7 @@
 // 	fix         update packages to use new APIs
 // 	fmt         gofmt (reformat) package sources
 // 	generate    generate Go files by processing source
-// 	get         add dependencies to current module and install them
+// 	get         download and install packages and dependencies
 // 	install     compile and install packages and dependencies
 // 	list        list packages or modules
 // 	mod         module maintenance
@@ -534,105 +534,67 @@
 // For more about specifying packages, see 'go help packages'.
 //
 //
-// Add dependencies to current module and install them
+// Download and install packages and dependencies
 //
 // Usage:
 //
-// 	go get [-d] [-m] [-u] [-v] [-insecure] [build flags] [packages]
+// 	go get [-d] [-f] [-t] [-u] [-v] [-fix] [-insecure] [build flags] [packages]
 //
-// Get resolves and adds dependencies to the current development module
-// and then builds and installs them.
+// Get downloads the packages named by the import paths, along with their
+// dependencies. It then installs the named packages, like 'go install'.
 //
-// The first step is to resolve which dependencies to add.
+// The -d flag instructs get to stop after downloading the packages; that is,
+// it instructs get not to install the packages.
 //
-// For each named package or package pattern, get must decide which version of
-// the corresponding module to use. By default, get chooses the latest tagged
-// release version, such as v0.4.5 or v1.2.3. If there are no tagged release
-// versions, get chooses the latest tagged prerelease version, such as
-// v0.0.1-pre1. If there are no tagged versions at all, get chooses the latest
-// known commit.
+// The -f flag, valid only when -u is set, forces get -u not to verify that
+// each package has been checked out from the source control repository
+// implied by its import path. This can be useful if the source is a local fork
+// of the original.
 //
-// This default version selection can be overridden by adding an @version
-// suffix to the package argument, as in 'go get golang.org/x/text@v0.3.0'.
-// For modules stored in source control repositories, the version suffix can
-// also be a commit hash, branch identifier, or other syntax known to the
-// source control system, as in 'go get golang.org/x/text@master'.
-// The version suffix @latest explicitly requests the default behavior
-// described above.
-//
-// If a module under consideration is already a dependency of the current
-// development module, then get will update the required version.
-// Specifying a version earlier than the current required version is valid and
-// downgrades the dependency. The version suffix @none indicates that the
-// dependency should be removed entirely, downgrading or removing modules
-// depending on it as needed.
-//
-// Although get defaults to using the latest version of the module containing
-// a named package, it does not use the latest version of that module's
-// dependencies. Instead it prefers to use the specific dependency versions
-// requested by that module. For example, if the latest A requires module
-// B v1.2.3, while B v1.2.4 and v1.3.1 are also available, then 'go get A'
-// will use the latest A but then use B v1.2.3, as requested by A. (If there
-// are competing requirements for a particular module, then 'go get' resolves
-// those requirements by taking the maximum requested version.)
-//
-// The -u flag instructs get to update dependencies to use newer minor or
-// patch releases when available. Continuing the previous example,
-// 'go get -u A' will use the latest A with B v1.3.1 (not B v1.2.3).
-//
-// The -u=patch flag (not -u patch) instructs get to update dependencies
-// to use newer patch releases when available. Continuing the previous example,
-// 'go get -u=patch A' will use the latest A with B v1.2.4 (not B v1.2.3).
-//
-// In general, adding a new dependency may require upgrading
-// existing dependencies to keep a working build, and 'go get' does
-// this automatically. Similarly, downgrading one dependency may
-// require downgrading other dependencies, and 'go get' does
-// this automatically as well.
-//
-// The -m flag instructs get to stop here, after resolving, upgrading,
-// and downgrading modules and updating go.mod. When using -m,
-// each specified package path must be a module path as well,
-// not the import path of a package below the module root.
+// The -fix flag instructs get to run the fix tool on the downloaded packages
+// before resolving dependencies or building the code.
 //
 // The -insecure flag permits fetching from repositories and resolving
 // custom domains using insecure schemes such as HTTP. Use with caution.
 //
-// The second step is to download (if needed), build, and install
-// the named packages.
+// The -t flag instructs get to also download the packages required to build
+// the tests for the specified packages.
 //
-// If an argument names a module but not a package (because there is no
-// Go source code in the module's root directory), then the install step
-// is skipped for that argument, instead of causing a build failure.
-// For example 'go get golang.org/x/perf' succeeds even though there
-// is no code corresponding to that import path.
+// The -u flag instructs get to use the network to update the named packages
+// and their dependencies. By default, get uses the network to check out
+// missing packages but does not use it to look for updates to existing packages.
 //
-// Note that package patterns are allowed and are expanded after resolving
-// the module versions. For example, 'go get golang.org/x/perf/cmd/...'
-// adds the latest golang.org/x/perf and then installs the commands in that
-// latest version.
+// The -v flag enables verbose progress and debug output.
 //
-// The -d flag instructs get to download the source code needed to build
-// the named packages, including downloading necessary dependencies,
-// but not to build and install them.
+// Get also accepts build flags to control the installation. See 'go help build'.
 //
-// With no package arguments, 'go get' applies to the main module,
-// and to the Go package in the current directory, if any. In particular,
-// 'go get -u' and 'go get -u=patch' update all the dependencies of the
-// main module. With no package arguments and also without -u,
-// 'go get' is not much more than 'go install', and 'go get -d' not much
-// more than 'go list'.
+// When checking out a new package, get creates the target directory
+// GOPATH/src/<import-path>. If the GOPATH contains multiple entries,
+// get uses the first one. For more details see: 'go help gopath'.
 //
-// For more about modules, see 'go help modules'.
+// When checking out or updating a package, get looks for a branch or tag
+// that matches the locally installed version of Go. The most important
+// rule is that if the local installation is running version "go1", get
+// searches for a branch or tag named "go1". If no such version exists
+// it retrieves the default branch of the package.
+//
+// When go get checks out or updates a Git repository,
+// it also updates any git submodules referenced by the repository.
+//
+// Get never checks out or updates code stored in vendor directories.
 //
 // For more about specifying packages, see 'go help packages'.
 //
-// This text describes the behavior of get using modules to manage source
-// code and dependencies. If instead the go command is running in GOPATH
-// mode, the details of get's flags and effects change, as does 'go help get'.
-// See 'go help modules' and 'go help gopath-get'.
+// For more about how 'go get' finds source code to
+// download, see 'go help importpath'.
 //
-// See also: go build, go install, go clean, go mod.
+// This text describes the behavior of get when using GOPATH
+// to manage source code and dependencies.
+// If instead the go command is running in module-aware mode,
+// the details of get's flags and effects change, as does 'go help get'.
+// See 'go help modules' and 'go help module-get'.
+//
+// See also: go build, go install, go clean.
 //
 //
 // Compile and install packages and dependencies
@@ -1876,72 +1838,6 @@
 // See https://golang.org/s/go15vendor for details.
 //
 //
-// Legacy GOPATH go get
-//
-// The 'go get' command changes behavior depending on whether the
-// go command is running in module-aware mode or legacy GOPATH mode.
-// This help text, accessible as 'go help gopath-get' even in module-aware mode,
-// describes 'go get' as it operates in legacy GOPATH mode.
-//
-// Usage: go get [-d] [-f] [-t] [-u] [-v] [-fix] [-insecure] [build flags] [packages]
-//
-// Get downloads the packages named by the import paths, along with their
-// dependencies. It then installs the named packages, like 'go install'.
-//
-// The -d flag instructs get to stop after downloading the packages; that is,
-// it instructs get not to install the packages.
-//
-// The -f flag, valid only when -u is set, forces get -u not to verify that
-// each package has been checked out from the source control repository
-// implied by its import path. This can be useful if the source is a local fork
-// of the original.
-//
-// The -fix flag instructs get to run the fix tool on the downloaded packages
-// before resolving dependencies or building the code.
-//
-// The -insecure flag permits fetching from repositories and resolving
-// custom domains using insecure schemes such as HTTP. Use with caution.
-//
-// The -t flag instructs get to also download the packages required to build
-// the tests for the specified packages.
-//
-// The -u flag instructs get to use the network to update the named packages
-// and their dependencies. By default, get uses the network to check out
-// missing packages but does not use it to look for updates to existing packages.
-//
-// The -v flag enables verbose progress and debug output.
-//
-// Get also accepts build flags to control the installation. See 'go help build'.
-//
-// When checking out a new package, get creates the target directory
-// GOPATH/src/<import-path>. If the GOPATH contains multiple entries,
-// get uses the first one. For more details see: 'go help gopath'.
-//
-// When checking out or updating a package, get looks for a branch or tag
-// that matches the locally installed version of Go. The most important
-// rule is that if the local installation is running version "go1", get
-// searches for a branch or tag named "go1". If no such version exists
-// it retrieves the default branch of the package.
-//
-// When go get checks out or updates a Git repository,
-// it also updates any git submodules referenced by the repository.
-//
-// Get never checks out or updates code stored in vendor directories.
-//
-// For more about specifying packages, see 'go help packages'.
-//
-// For more about how 'go get' finds source code to
-// download, see 'go help importpath'.
-//
-// This text describes the behavior of get when using GOPATH
-// to manage source code and dependencies.
-// If instead the go command is running in module-aware mode,
-// the details of get's flags and effects change, as does 'go help get'.
-// See 'go help modules' and 'go help module-get'.
-//
-// See also: go build, go install, go clean.
-//
-//
 // Module proxy protocol
 //
 // The go command by default downloads modules from version control systems
@@ -2201,25 +2097,34 @@
 // Modules replace the old GOPATH-based approach to specifying
 // which source files are used in a given build.
 //
-// Module support
+// Preliminary module support
 //
-// Go 1.13 includes official support for Go modules,
-// including a module-aware 'go get' command.
-// Module-aware mode is active by default.
+// Go 1.11 includes preliminary support for Go modules,
+// including a new module-aware 'go get' command.
+// We intend to keep revising this support, while preserving compatibility,
+// until it can be declared official (no longer preliminary),
+// and then at a later point we may remove support for work
+// in GOPATH and the old 'go get' command.
 //
-// For more fine-grained control, Go 1.13 continues to respect
+// The quickest way to take advantage of the new Go 1.11 module support
+// is to check out your repository into a directory outside GOPATH/src,
+// create a go.mod file (described in the next section) there, and run
+// go commands from within that file tree.
+//
+// For more fine-grained control, the module support in Go 1.11 respects
 // a temporary environment variable, GO111MODULE, which can be set to one
-// of three string values: off, auto, or on (the default).
-// If GO111MODULE=on or is unset, then the go command requires the use of
-// modules, never consulting GOPATH. We refer to this as the command
-// being module-aware or running in "module-aware mode".
-// If GO111MODULE=auto, then the go command enables or disables module
-// support based on the current directory. Module support is enabled only
-// when the current directory is outside GOPATH/src and itself contains a
-// go.mod file or is below a directory containing a go.mod file.
-// If GO111MODULE=off, then the go command never uses
-// module support. Instead it looks in vendor directories and GOPATH
+// of three string values: off, on, or auto (the default).
+// If GO111MODULE=off, then the go command never uses the
+// new module support. Instead it looks in vendor directories and GOPATH
 // to find dependencies; we now refer to this as "GOPATH mode."
+// If GO111MODULE=on, then the go command requires the use of modules,
+// never consulting GOPATH. We refer to this as the command being
+// module-aware or running in "module-aware mode".
+// If GO111MODULE=auto or is unset, then the go command enables or
+// disables module support based on the current directory.
+// Module support is enabled only when the current directory is outside
+// GOPATH/src and itself contains a go.mod file or is below a directory
+// containing a go.mod file.
 //
 // In module-aware mode, GOPATH no longer defines the meaning of imports
 // during a build, but it still stores downloaded dependencies (in GOPATH/pkg/mod)
@@ -2541,6 +2446,110 @@
 // are still ignored.
 //
 //
+// Module-aware go get
+//
+// The 'go get' command changes behavior depending on whether the
+// go command is running in module-aware mode or legacy GOPATH mode.
+// This help text, accessible as 'go help module-get' even in legacy GOPATH mode,
+// describes 'go get' as it operates in module-aware mode.
+//
+// Usage: go get [-d] [-m] [-u] [-v] [-insecure] [build flags] [packages]
+//
+// Get resolves and adds dependencies to the current development module
+// and then builds and installs them.
+//
+// The first step is to resolve which dependencies to add.
+//
+// For each named package or package pattern, get must decide which version of
+// the corresponding module to use. By default, get chooses the latest tagged
+// release version, such as v0.4.5 or v1.2.3. If there are no tagged release
+// versions, get chooses the latest tagged prerelease version, such as
+// v0.0.1-pre1. If there are no tagged versions at all, get chooses the latest
+// known commit.
+//
+// This default version selection can be overridden by adding an @version
+// suffix to the package argument, as in 'go get golang.org/x/text@v0.3.0'.
+// For modules stored in source control repositories, the version suffix can
+// also be a commit hash, branch identifier, or other syntax known to the
+// source control system, as in 'go get golang.org/x/text@master'.
+// The version suffix @latest explicitly requests the default behavior
+// described above.
+//
+// If a module under consideration is already a dependency of the current
+// development module, then get will update the required version.
+// Specifying a version earlier than the current required version is valid and
+// downgrades the dependency. The version suffix @none indicates that the
+// dependency should be removed entirely, downgrading or removing modules
+// depending on it as needed.
+//
+// Although get defaults to using the latest version of the module containing
+// a named package, it does not use the latest version of that module's
+// dependencies. Instead it prefers to use the specific dependency versions
+// requested by that module. For example, if the latest A requires module
+// B v1.2.3, while B v1.2.4 and v1.3.1 are also available, then 'go get A'
+// will use the latest A but then use B v1.2.3, as requested by A. (If there
+// are competing requirements for a particular module, then 'go get' resolves
+// those requirements by taking the maximum requested version.)
+//
+// The -u flag instructs get to update dependencies to use newer minor or
+// patch releases when available. Continuing the previous example,
+// 'go get -u A' will use the latest A with B v1.3.1 (not B v1.2.3).
+//
+// The -u=patch flag (not -u patch) instructs get to update dependencies
+// to use newer patch releases when available. Continuing the previous example,
+// 'go get -u=patch A' will use the latest A with B v1.2.4 (not B v1.2.3).
+//
+// In general, adding a new dependency may require upgrading
+// existing dependencies to keep a working build, and 'go get' does
+// this automatically. Similarly, downgrading one dependency may
+// require downgrading other dependencies, and 'go get' does
+// this automatically as well.
+//
+// The -m flag instructs get to stop here, after resolving, upgrading,
+// and downgrading modules and updating go.mod. When using -m,
+// each specified package path must be a module path as well,
+// not the import path of a package below the module root.
+//
+// The -insecure flag permits fetching from repositories and resolving
+// custom domains using insecure schemes such as HTTP. Use with caution.
+//
+// The second step is to download (if needed), build, and install
+// the named packages.
+//
+// If an argument names a module but not a package (because there is no
+// Go source code in the module's root directory), then the install step
+// is skipped for that argument, instead of causing a build failure.
+// For example 'go get golang.org/x/perf' succeeds even though there
+// is no code corresponding to that import path.
+//
+// Note that package patterns are allowed and are expanded after resolving
+// the module versions. For example, 'go get golang.org/x/perf/cmd/...'
+// adds the latest golang.org/x/perf and then installs the commands in that
+// latest version.
+//
+// The -d flag instructs get to download the source code needed to build
+// the named packages, including downloading necessary dependencies,
+// but not to build and install them.
+//
+// With no package arguments, 'go get' applies to the main module,
+// and to the Go package in the current directory, if any. In particular,
+// 'go get -u' and 'go get -u=patch' update all the dependencies of the
+// main module. With no package arguments and also without -u,
+// 'go get' is not much more than 'go install', and 'go get -d' not much
+// more than 'go list'.
+//
+// For more about modules, see 'go help modules'.
+//
+// For more about specifying packages, see 'go help packages'.
+//
+// This text describes the behavior of get using modules to manage source
+// code and dependencies. If instead the go command is running in GOPATH
+// mode, the details of get's flags and effects change, as does 'go help get'.
+// See 'go help modules' and 'go help gopath-get'.
+//
+// See also: go build, go install, go clean, go mod.
+//
+//
 // Package lists and patterns
 //
 // Many commands apply to a set of packages:
diff --git a/src/cmd/go/help_test.go b/src/cmd/go/help_test.go
index 9c0fa8411e..ec6a9d11cb 100644
--- a/src/cmd/go/help_test.go
+++ b/src/cmd/go/help_test.go
@@ -12,14 +12,9 @@ import (
 	"testing"
 
 	"cmd/go/internal/help"
-	"cmd/go/internal/modload"
 )
 
 func TestDocsUpToDate(t *testing.T) {
-	if !modload.Enabled() {
-		t.Skipf("help.Help in GOPATH mode is configured by main.main")
-	}
-
 	buf := new(bytes.Buffer)
 	// Match the command in mkalldocs.sh that generates alldocs.go.
 	help.Help(buf, []string{"documentation"})
diff --git a/src/cmd/go/internal/help/help.go b/src/cmd/go/internal/help/help.go
index d373771ab5..121deb70a5 100644
--- a/src/cmd/go/internal/help/help.go
+++ b/src/cmd/go/internal/help/help.go
@@ -17,7 +17,6 @@ import (
 	"unicode/utf8"
 
 	"cmd/go/internal/base"
-	"cmd/go/internal/modload"
 )
 
 // Help implements the 'help' command.
@@ -36,10 +35,8 @@ func Help(w io.Writer, args []string) {
 		usage := &base.Command{Long: buf.String()}
 		cmds := []*base.Command{usage}
 		for _, cmd := range base.Go.Commands {
-			// Avoid duplication of the "get" documentation.
-			if cmd.UsageLine == "module-get" && modload.Enabled() {
-				continue
-			} else if cmd.UsageLine == "gopath-get" && !modload.Enabled() {
+			if cmd.UsageLine == "gopath-get" {
+				// Avoid duplication of the "get" documentation.
 				continue
 			}
 			cmds = append(cmds, cmd)
diff --git a/src/cmd/go/internal/modload/help.go b/src/cmd/go/internal/modload/help.go
index c1685ff08e..63657a448f 100644
--- a/src/cmd/go/internal/modload/help.go
+++ b/src/cmd/go/internal/modload/help.go
@@ -19,25 +19,34 @@ including recording and resolving dependencies on other modules.
 Modules replace the old GOPATH-based approach to specifying
 which source files are used in a given build.
 
-Module support
+Preliminary module support
 
-Go 1.13 includes official support for Go modules,
-including a module-aware 'go get' command.
-Module-aware mode is active by default.
+Go 1.11 includes preliminary support for Go modules,
+including a new module-aware 'go get' command.
+We intend to keep revising this support, while preserving compatibility,
+until it can be declared official (no longer preliminary),
+and then at a later point we may remove support for work
+in GOPATH and the old 'go get' command.
 
-For more fine-grained control, Go 1.13 continues to respect
+The quickest way to take advantage of the new Go 1.11 module support
+is to check out your repository into a directory outside GOPATH/src,
+create a go.mod file (described in the next section) there, and run
+go commands from within that file tree.
+
+For more fine-grained control, the module support in Go 1.11 respects
 a temporary environment variable, GO111MODULE, which can be set to one
-of three string values: off, auto, or on (the default).
-If GO111MODULE=on or is unset, then the go command requires the use of
-modules, never consulting GOPATH. We refer to this as the command
-being module-aware or running in "module-aware mode".
-If GO111MODULE=auto, then the go command enables or disables module
-support based on the current directory. Module support is enabled only
-when the current directory is outside GOPATH/src and itself contains a
-go.mod file or is below a directory containing a go.mod file.
-If GO111MODULE=off, then the go command never uses
-module support. Instead it looks in vendor directories and GOPATH
+of three string values: off, on, or auto (the default).
+If GO111MODULE=off, then the go command never uses the
+new module support. Instead it looks in vendor directories and GOPATH
 to find dependencies; we now refer to this as "GOPATH mode."
+If GO111MODULE=on, then the go command requires the use of modules,
+never consulting GOPATH. We refer to this as the command being
+module-aware or running in "module-aware mode".
+If GO111MODULE=auto or is unset, then the go command enables or
+disables module support based on the current directory.
+Module support is enabled only when the current directory is outside
+GOPATH/src and itself contains a go.mod file or is below a directory
+containing a go.mod file.
 
 In module-aware mode, GOPATH no longer defines the meaning of imports
 during a build, but it still stores downloaded dependencies (in GOPATH/pkg/mod)
diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index ddfb18738f..0970ccf2d6 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -34,7 +34,7 @@ import (
 
 var (
 	cwd            string // TODO(bcmills): Is this redundant with base.Cwd?
-	mustUseModules = true
+	MustUseModules = mustUseModules()
 	initialized    bool
 
 	modRoot     string
@@ -70,6 +70,16 @@ func BinDir() string {
 	return filepath.Join(gopath, "bin")
 }
 
+// mustUseModules reports whether we are invoked as vgo
+// (as opposed to go).
+// If so, we only support builds with go.mod files.
+func mustUseModules() bool {
+	name := os.Args[0]
+	name = name[strings.LastIndex(name, "/")+1:]
+	name = name[strings.LastIndex(name, `\`)+1:]
+	return strings.HasPrefix(name, "vgo")
+}
+
 var inGOPATH bool // running in GOPATH/src
 
 // Init determines whether module mode is enabled, locates the root of the
@@ -86,13 +96,14 @@ func Init() {
 	switch env {
 	default:
 		base.Fatalf("go: unknown environment setting GO111MODULE=%s", env)
-	case "auto":
-		mustUseModules = false
-	case "on", "":
-		mustUseModules = true
+	case "", "auto":
+		// leave MustUseModules alone
+	case "on":
+		MustUseModules = true
 	case "off":
-		mustUseModules = false
-		return
+		if !MustUseModules {
+			return
+		}
 	}
 
 	// Disable any prompting for passwords by Git.
@@ -139,7 +150,7 @@ func Init() {
 		}
 	}
 
-	if inGOPATH && !mustUseModules {
+	if inGOPATH && !MustUseModules {
 		if CmdModInit {
 			die() // Don't init a module that we're just going to ignore.
 		}
@@ -156,8 +167,8 @@ func Init() {
 	} else {
 		modRoot = findModuleRoot(cwd)
 		if modRoot == "" {
-			if !mustUseModules {
-				// GO111MODULE is 'auto', and we can't find a module root.
+			if !MustUseModules {
+				// GO111MODULE is 'auto' (or unset), and we can't find a module root.
 				// Stay in GOPATH mode.
 				return
 			}
@@ -256,7 +267,7 @@ func init() {
 // (usually through MustModRoot).
 func Enabled() bool {
 	Init()
-	return modRoot != "" || mustUseModules
+	return modRoot != "" || MustUseModules
 }
 
 // ModRoot returns the root of the main module.
@@ -289,7 +300,7 @@ func die() {
 	if os.Getenv("GO111MODULE") == "off" {
 		base.Fatalf("go: modules disabled by GO111MODULE=off; see 'go help modules'")
 	}
-	if inGOPATH && !mustUseModules {
+	if inGOPATH && !MustUseModules {
 		base.Fatalf("go: modules disabled inside GOPATH/src by GO111MODULE=auto; see 'go help modules'")
 	}
 	if cwd != "" {
diff --git a/src/cmd/go/main.go b/src/cmd/go/main.go
index e529e96986..acca4fd3c1 100644
--- a/src/cmd/go/main.go
+++ b/src/cmd/go/main.go
@@ -49,7 +49,7 @@ func init() {
 		fix.CmdFix,
 		fmtcmd.CmdFmt,
 		generate.CmdGenerate,
-		modget.CmdGet,
+		get.CmdGet,
 		work.CmdInstall,
 		list.CmdList,
 		modcmd.CmdMod,
@@ -89,10 +89,17 @@ func main() {
 		base.Usage()
 	}
 
+	if modload.MustUseModules {
+		// If running with modules force-enabled, change get now to change help message.
+		*get.CmdGet = *modget.CmdGet
+	}
+
 	if args[0] == "get" || args[0] == "help" {
-		if modload.Init(); !modload.Enabled() {
-			// Replace module-aware get with GOPATH get if appropriate.
-			*modget.CmdGet = *get.CmdGet
+		// Replace get with module-aware get if appropriate.
+		// Note that if MustUseModules is true, this happened already above,
+		// but no harm in doing it again.
+		if modload.Init(); modload.Enabled() {
+			*get.CmdGet = *modget.CmdGet
 		}
 	}
 
diff --git a/src/cmd/go/mkalldocs.sh b/src/cmd/go/mkalldocs.sh
index a2b0aca3c9..f37d59d2d7 100755
--- a/src/cmd/go/mkalldocs.sh
+++ b/src/cmd/go/mkalldocs.sh
@@ -8,6 +8,6 @@ set -e
 go build -o go.latest
 # If the command used to generate alldocs.go changes, update TestDocsUpToDate in
 # help_test.go.
-GO111MODULE='' ./go.latest help documentation >alldocs.go
+./go.latest help documentation >alldocs.go
 gofmt -w alldocs.go
 rm go.latest
diff --git a/src/cmd/go/testdata/script/mod_find.txt b/src/cmd/go/testdata/script/mod_find.txt
index e82001a24a..703a88e99c 100644
--- a/src/cmd/go/testdata/script/mod_find.txt
+++ b/src/cmd/go/testdata/script/mod_find.txt
@@ -17,7 +17,7 @@ cd $GOPATH/src/example.com/x/y
 ! go mod init
 stderr 'go: modules disabled inside GOPATH/src by GO111MODULE=auto; see ''go help modules'''
 
-env GO111MODULE=
+env GO111MODULE=on
 
 # Derive module path from location inside GOPATH.
 cd $GOPATH/src/example.com/x/y
diff --git a/src/cmd/go/testdata/script/mod_gobuild_import.txt b/src/cmd/go/testdata/script/mod_gobuild_import.txt
index 6c87d59649..d2d1645b83 100644
--- a/src/cmd/go/testdata/script/mod_gobuild_import.txt
+++ b/src/cmd/go/testdata/script/mod_gobuild_import.txt
@@ -24,18 +24,12 @@ exec $WORK/testimport.exe other/x/y/z/w .
 stdout w2.go
 
 # GO111MODULE=on outside GOPATH/src
-env GO111MODULE=
-exec $WORK/testimport.exe other/x/y/z/w .
-stdout w2.go
 env GO111MODULE=on
 exec $WORK/testimport.exe other/x/y/z/w .
 stdout w2.go
 
 # GO111MODULE=on in GOPATH/src
 cd $GOPATH/src
-env GO111MODULE=
-exec $WORK/testimport.exe x/y/z/w .
-stdout w1.go
 env GO111MODULE=on
 exec $WORK/testimport.exe x/y/z/w .
 stdout w1.go