diff --git a/src/cmd/gofmt/rewrite.go b/src/cmd/gofmt/rewrite.go
index 79b7858..bab22e0 100644
--- a/src/cmd/gofmt/rewrite.go
+++ b/src/cmd/gofmt/rewrite.go
@@ -271,6 +271,12 @@
 	// Otherwise copy.
 	switch p := pattern; p.Kind() {
 	case reflect.Slice:
+		if p.IsNil() {
+			// Do not turn nil slices into empty slices. go/ast
+			// guarantees that certain lists will be nil if not
+			// populated.
+			return reflect.Zero(p.Type())
+		}
 		v := reflect.MakeSlice(p.Type(), p.Len(), p.Len())
 		for i := 0; i < p.Len(); i++ {
 			v.Index(i).Set(subst(m, p.Index(i), pos))
diff --git a/src/cmd/gofmt/testdata/rewrite10.golden b/src/cmd/gofmt/testdata/rewrite10.golden
new file mode 100644
index 0000000..1dd781f
--- /dev/null
+++ b/src/cmd/gofmt/testdata/rewrite10.golden
@@ -0,0 +1,19 @@
+//gofmt -r=a->a
+
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 33103, 33104, and 33105.
+
+package pkg
+
+func fn() {
+	_ = func() {
+		switch {
+		default:
+		}
+	}
+	_ = func() string {}
+	_ = func() { var ptr *string; println(ptr) }
+}
diff --git a/src/cmd/gofmt/testdata/rewrite10.input b/src/cmd/gofmt/testdata/rewrite10.input
new file mode 100644
index 0000000..1dd781f
--- /dev/null
+++ b/src/cmd/gofmt/testdata/rewrite10.input
@@ -0,0 +1,19 @@
+//gofmt -r=a->a
+
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 33103, 33104, and 33105.
+
+package pkg
+
+func fn() {
+	_ = func() {
+		switch {
+		default:
+		}
+	}
+	_ = func() string {}
+	_ = func() { var ptr *string; println(ptr) }
+}