diff --git a/go/analysis/passes/reflectvaluecompare/reflectvaluecompare.go b/go/analysis/passes/reflectvaluecompare/reflectvaluecompare.go
new file mode 100644
index 0000000..ef21f0e
--- /dev/null
+++ b/go/analysis/passes/reflectvaluecompare/reflectvaluecompare.go
@@ -0,0 +1,99 @@
+// Copyright 2021 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.
+
+// Package reflectvaluecompare defines an Analyzer that checks for accidentally
+// using == or reflect.DeepEqual to compare reflect.Value values.
+// See issues 43993 and 18871.
+package reflectvaluecompare
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/inspect"
+	"golang.org/x/tools/go/ast/inspector"
+	"golang.org/x/tools/go/types/typeutil"
+)
+
+const Doc = `check for comparing reflect.Value values with == or reflect.DeepEqual
+
+The reflectvaluecompare checker looks for expressions of the form:
+
+    v1 == v2
+    v1 != v2
+    reflect.DeepEqual(v1, v2)
+
+where v1 or v2 are reflect.Values. Comparing reflect.Values directly
+is almost certainly not correct, as it compares the reflect package's
+internal representation, not the underlying value.
+Likely what is intended is:
+
+    v1.Interface() == v2.Interface()
+    v1.Interface() != v2.Interface()
+    reflect.DeepEqual(v1.Interface(), v2.Interface())
+`
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "reflectvaluecompare",
+	Doc:      Doc,
+	Requires: []*analysis.Analyzer{inspect.Analyzer},
+	Run:      run,
+}
+
+func run(pass *analysis.Pass) (interface{}, error) {
+	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+
+	nodeFilter := []ast.Node{
+		(*ast.BinaryExpr)(nil),
+		(*ast.CallExpr)(nil),
+	}
+	inspect.Preorder(nodeFilter, func(n ast.Node) {
+		switch n := n.(type) {
+		case *ast.BinaryExpr:
+			if n.Op != token.EQL && n.Op != token.NEQ {
+				return
+			}
+			if isReflectValue(pass, n.X) || isReflectValue(pass, n.Y) {
+				if n.Op == token.EQL {
+					pass.ReportRangef(n, "avoid using == with reflect.Value")
+				} else {
+					pass.ReportRangef(n, "avoid using != with reflect.Value")
+				}
+			}
+		case *ast.CallExpr:
+			fn, ok := typeutil.Callee(pass.TypesInfo, n).(*types.Func)
+			if !ok {
+				return
+			}
+			if fn.FullName() == "reflect.DeepEqual" && (isReflectValue(pass, n.Args[0]) || isReflectValue(pass, n.Args[1])) {
+				pass.ReportRangef(n, "avoid using reflect.DeepEqual with reflect.Value")
+			}
+		}
+	})
+	return nil, nil
+}
+
+// isReflectValue reports whether the type of e is reflect.Value.
+func isReflectValue(pass *analysis.Pass, e ast.Expr) bool {
+	tv, ok := pass.TypesInfo.Types[e]
+	if !ok { // no type info, something else is wrong
+		return false
+	}
+	// See if the type is reflect.Value
+	named, ok := tv.Type.(*types.Named)
+	if !ok {
+		return false
+	}
+	if obj := named.Obj(); obj == nil || obj.Pkg() == nil || obj.Pkg().Path() != "reflect" || obj.Name() != "Value" {
+		return false
+	}
+	if _, ok := e.(*ast.CompositeLit); ok {
+		// This is reflect.Value{}. Don't treat that as an error.
+		// Users should probably use x.IsValid() rather than x == reflect.Value{}, but the latter isn't wrong.
+		return false
+	}
+	return true
+}
diff --git a/go/analysis/passes/reflectvaluecompare/reflectvaluecompare_test.go b/go/analysis/passes/reflectvaluecompare/reflectvaluecompare_test.go
new file mode 100644
index 0000000..88fc8f2
--- /dev/null
+++ b/go/analysis/passes/reflectvaluecompare/reflectvaluecompare_test.go
@@ -0,0 +1,17 @@
+// Copyright 2021 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.
+
+package reflectvaluecompare_test
+
+import (
+	"testing"
+
+	"golang.org/x/tools/go/analysis/analysistest"
+	"golang.org/x/tools/go/analysis/passes/reflectvaluecompare"
+)
+
+func TestReflectValueCompare(t *testing.T) {
+	testdata := analysistest.TestData()
+	analysistest.Run(t, testdata, reflectvaluecompare.Analyzer, "a")
+}
diff --git a/go/analysis/passes/reflectvaluecompare/testdata/src/a/a.go b/go/analysis/passes/reflectvaluecompare/testdata/src/a/a.go
new file mode 100644
index 0000000..e069c6d
--- /dev/null
+++ b/go/analysis/passes/reflectvaluecompare/testdata/src/a/a.go
@@ -0,0 +1,51 @@
+// Copyright 2021 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.
+
+// This file contains tests for the reflectvaluecompare checker.
+
+package a
+
+import (
+	"reflect"
+)
+
+func f() {
+	var x, y reflect.Value
+	var a, b interface{}
+	_ = x == y // want `avoid using == with reflect.Value`
+	_ = x == a // want `avoid using == with reflect.Value`
+	_ = a == x // want `avoid using == with reflect.Value`
+	_ = a == b
+
+	// Comparing to reflect.Value{} is ok.
+	_ = a == reflect.Value{}
+	_ = reflect.Value{} == a
+	_ = reflect.Value{} == reflect.Value{}
+}
+func g() {
+	var x, y reflect.Value
+	var a, b interface{}
+	_ = x != y // want `avoid using != with reflect.Value`
+	_ = x != a // want `avoid using != with reflect.Value`
+	_ = a != x // want `avoid using != with reflect.Value`
+	_ = a != b
+
+	// Comparing to reflect.Value{} is ok.
+	_ = a != reflect.Value{}
+	_ = reflect.Value{} != a
+	_ = reflect.Value{} != reflect.Value{}
+}
+func h() {
+	var x, y reflect.Value
+	var a, b interface{}
+	reflect.DeepEqual(x, y) // want `avoid using reflect.DeepEqual with reflect.Value`
+	reflect.DeepEqual(x, a) // want `avoid using reflect.DeepEqual with reflect.Value`
+	reflect.DeepEqual(a, x) // want `avoid using reflect.DeepEqual with reflect.Value`
+	reflect.DeepEqual(a, b)
+
+	// Comparing to reflect.Value{} is ok.
+	reflect.DeepEqual(reflect.Value{}, a)
+	reflect.DeepEqual(a, reflect.Value{})
+	reflect.DeepEqual(reflect.Value{}, reflect.Value{})
+}