diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index da778b4fad..7e8c223189 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -25,7 +25,6 @@ import (
 	"path"
 	"path/filepath"
 	"regexp"
-	"runtime"
 	"strconv"
 	"strings"
 )
@@ -402,7 +401,7 @@ func FindModuleRoot(dir, limit string, legacyConfigOK bool) (root, file string)
 
 	// Look for enclosing go.mod.
 	for {
-		if fi, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil && !(runtime.GOOS == "plan9" && fi.IsDir()) {
+		if fi, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil && !fi.IsDir() {
 			return dir, "go.mod"
 		}
 		if dir == limit {
@@ -420,7 +419,7 @@ func FindModuleRoot(dir, limit string, legacyConfigOK bool) (root, file string)
 		dir = dir1
 		for {
 			for _, name := range altConfigs {
-				if fi, err := os.Stat(filepath.Join(dir, name)); err == nil && !(runtime.GOOS == "plan9" && fi.IsDir()) {
+				if fi, err := os.Stat(filepath.Join(dir, name)); err == nil && !fi.IsDir() {
 					return dir, name
 				}
 			}
diff --git a/src/cmd/go/internal/modload/init_plan9_test.go b/src/cmd/go/internal/modload/init_test.go
similarity index 100%
rename from src/cmd/go/internal/modload/init_plan9_test.go
rename to src/cmd/go/internal/modload/init_test.go