diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go
index d68f43a7c98..fdc00f95dca 100644
--- a/src/cmd/go/internal/load/pkg.go
+++ b/src/cmd/go/internal/load/pkg.go
@@ -3001,7 +3001,7 @@ func PackagesAndErrorsOutsideModule(ctx context.Context, opts PackageOpts, args
 	patterns := make([]string, len(args))
 	for i, arg := range args {
 		if !strings.HasSuffix(arg, "@"+version) {
-			return nil, fmt.Errorf("%s: all arguments must have the same version (@%s)", arg, version)
+			return nil, fmt.Errorf("%s: all arguments must refer to packages in the same module at the same version (@%s)", arg, version)
 		}
 		p := arg[:len(arg)-len(version)-1]
 		switch {
diff --git a/src/cmd/go/testdata/script/mod_install_pkg_version.txt b/src/cmd/go/testdata/script/mod_install_pkg_version.txt
index 14153b8e9ec..e3f59fc1528 100644
--- a/src/cmd/go/testdata/script/mod_install_pkg_version.txt
+++ b/src/cmd/go/testdata/script/mod_install_pkg_version.txt
@@ -106,7 +106,7 @@ stdout '^example.com/cmd v1.0.0$'
 env GO111MODULE=auto
 
 ! go install example.com/cmd/a@v1.0.0 example.com/cmd/b@latest
-stderr '^go: example.com/cmd/b@latest: all arguments must have the same version \(@v1.0.0\)$'
+stderr '^go: example.com/cmd/b@latest: all arguments must refer to packages in the same module at the same version \(@v1.0.0\)$'
 
 
 # 'go install pkg@version' should report an error if the arguments are in