diff --git a/src/cmd/go/testdata/script/fmt_load_errors.txt b/src/cmd/go/testdata/script/fmt_load_errors.txt
index 297ec0fe3c..84bf41cfba 100644
--- a/src/cmd/go/testdata/script/fmt_load_errors.txt
+++ b/src/cmd/go/testdata/script/fmt_load_errors.txt
@@ -6,6 +6,17 @@ go fmt -n exclude
 stdout 'exclude[/\\]x\.go'
 stdout 'exclude[/\\]x_linux\.go'
 
+# Test edge cases with gofmt.
+# Note that this execs GOROOT/bin/gofmt.
+
+! exec gofmt does-not-exist
+
+exec gofmt gofmt-dir/no-extension
+stdout 'package x'
+
+exec gofmt gofmt-dir
+! stdout 'package x'
+
 -- exclude/empty/x.txt --
 -- exclude/ignore/_x.go --
 package x
@@ -17,3 +28,5 @@ package x
 // +build windows
 
 package x
+-- gofmt-dir/no-extension --
+package x
diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
index fef86c941f..b3c120daab 100644
--- a/src/cmd/gofmt/gofmt.go
+++ b/src/cmd/gofmt/gofmt.go
@@ -214,8 +214,19 @@ func gofmtMain() {
 	}
 
 	for _, arg := range args {
-		if err := filepath.WalkDir(arg, visitFile); err != nil {
+		switch info, err := os.Stat(arg); {
+		case err != nil:
 			report(err)
+		case !info.IsDir():
+			// Non-directory arguments are always formatted.
+			if err := processFile(arg, nil, os.Stdout, false); err != nil {
+				report(err)
+			}
+		default:
+			// Directories are walked, ignoring non-Go files.
+			if err := filepath.WalkDir(arg, visitFile); err != nil {
+				report(err)
+			}
 		}
 	}
 }