diff --git a/packages/ast-spec/src/expression/AssignmentExpression/AssignmentOperatorToText.ts b/packages/ast-spec/src/expression/AssignmentExpression/AssignmentOperatorToText.ts
new file mode 100644
index 000000000000..a0c723aa1f30
--- /dev/null
+++ b/packages/ast-spec/src/expression/AssignmentExpression/AssignmentOperatorToText.ts
@@ -0,0 +1,20 @@
+import type { SyntaxKind } from 'typescript';
+
+export interface AssignmentOperatorToText {
+  [SyntaxKind.EqualsToken]: '=';
+  [SyntaxKind.PlusEqualsToken]: '+=';
+  [SyntaxKind.MinusEqualsToken]: '-=';
+  [SyntaxKind.AsteriskEqualsToken]: '*=';
+  [SyntaxKind.AsteriskAsteriskEqualsToken]: '**=';
+  [SyntaxKind.SlashEqualsToken]: '/=';
+  [SyntaxKind.PercentEqualsToken]: '%=';
+  [SyntaxKind.LessThanLessThanEqualsToken]: '<<=';
+  [SyntaxKind.GreaterThanGreaterThanEqualsToken]: '>>=';
+  [SyntaxKind.GreaterThanGreaterThanGreaterThanEqualsToken]: '>>>=';
+  [SyntaxKind.AmpersandEqualsToken]: '&=';
+  [SyntaxKind.BarEqualsToken]: '|=';
+  [SyntaxKind.BarBarEqualsToken]: '||='; // included in PunctuationSyntaxKind in TS 4.4
+  [SyntaxKind.AmpersandAmpersandEqualsToken]: '&&='; // included in PunctuationSyntaxKind in TS 4.4
+  [SyntaxKind.QuestionQuestionEqualsToken]: '??='; // included in PunctuationSyntaxKind in TS 4.4
+  [SyntaxKind.CaretEqualsToken]: '^=';
+}
diff --git a/packages/ast-spec/src/expression/AssignmentExpression/spec.ts b/packages/ast-spec/src/expression/AssignmentExpression/spec.ts
index 8d76be21bdcc..03420505a506 100644
--- a/packages/ast-spec/src/expression/AssignmentExpression/spec.ts
+++ b/packages/ast-spec/src/expression/AssignmentExpression/spec.ts
@@ -1,23 +1,11 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
 import type { BinaryExpressionBase } from '../../base/BinaryExpressionBase';
+import type { ValueOf } from '../../utils';
+import type { AssignmentOperatorToText } from './AssignmentOperatorToText';
+
+export * from './AssignmentOperatorToText';
 
 export interface AssignmentExpression extends BinaryExpressionBase {
   type: AST_NODE_TYPES.AssignmentExpression;
-  operator:
-    | '-='
-    | '??='
-    | '**='
-    | '*='
-    | '/='
-    | '&&='
-    | '&='
-    | '%='
-    | '^='
-    | '+='
-    | '<<='
-    | '='
-    | '>>='
-    | '>>>='
-    | '|='
-    | '||=';
+  operator: ValueOf<AssignmentOperatorToText>;
 }
diff --git a/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts b/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts
index d15682a4efe7..a3ea5b151613 100644
--- a/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts
+++ b/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts
@@ -1,6 +1,8 @@
 import type { SyntaxKind } from 'typescript';
 
-export interface PunctuatorTokenToText {
+import type { AssignmentOperatorToText } from '../../expression/AssignmentExpression/AssignmentOperatorToText';
+
+export interface PunctuatorTokenToText extends AssignmentOperatorToText {
   [SyntaxKind.OpenBraceToken]: '{';
   [SyntaxKind.CloseBraceToken]: '}';
   [SyntaxKind.OpenParenToken]: '(';
@@ -46,20 +48,4 @@ export interface PunctuatorTokenToText {
   [SyntaxKind.QuestionQuestionToken]: '??';
   [SyntaxKind.BacktickToken]: '`';
   [SyntaxKind.HashToken]: '#';
-  [SyntaxKind.EqualsToken]: '=';
-  [SyntaxKind.PlusEqualsToken]: '+=';
-  [SyntaxKind.MinusEqualsToken]: '-=';
-  [SyntaxKind.AsteriskEqualsToken]: '*=';
-  [SyntaxKind.AsteriskAsteriskEqualsToken]: '**=';
-  [SyntaxKind.SlashEqualsToken]: '/=';
-  [SyntaxKind.PercentEqualsToken]: '%=';
-  [SyntaxKind.LessThanLessThanEqualsToken]: '<<=';
-  [SyntaxKind.GreaterThanGreaterThanEqualsToken]: '>>=';
-  [SyntaxKind.GreaterThanGreaterThanGreaterThanEqualsToken]: '>>>=';
-  [SyntaxKind.AmpersandEqualsToken]: '&=';
-  [SyntaxKind.BarEqualsToken]: '|=';
-  [SyntaxKind.BarBarEqualsToken]: '||=';
-  [SyntaxKind.AmpersandAmpersandEqualsToken]: '&&=';
-  [SyntaxKind.QuestionQuestionEqualsToken]: '??=';
-  [SyntaxKind.CaretEqualsToken]: '^=';
 }
diff --git a/packages/ast-spec/src/token/PunctuatorToken/spec.ts b/packages/ast-spec/src/token/PunctuatorToken/spec.ts
index 68156aad6638..733e0108d2f4 100644
--- a/packages/ast-spec/src/token/PunctuatorToken/spec.ts
+++ b/packages/ast-spec/src/token/PunctuatorToken/spec.ts
@@ -1,11 +1,10 @@
 import type { AST_TOKEN_TYPES } from '../../ast-token-types';
 import type { BaseToken } from '../../base/BaseToken';
+import type { ValueOf } from '../../utils';
 import type { PunctuatorTokenToText } from './PunctuatorTokenToText';
 
 export * from './PunctuatorTokenToText';
 
-type ValueOf<T> = T[keyof T];
-
 export interface PunctuatorToken extends BaseToken {
   type: AST_TOKEN_TYPES.Punctuator;
   value: ValueOf<PunctuatorTokenToText>;
diff --git a/packages/ast-spec/src/utils.ts b/packages/ast-spec/src/utils.ts
new file mode 100644
index 000000000000..5f2cf2cf07f3
--- /dev/null
+++ b/packages/ast-spec/src/utils.ts
@@ -0,0 +1 @@
+export type ValueOf<T> = T[keyof T];
diff --git a/packages/ast-spec/tests/AssignmentOperatorToText.test.ts b/packages/ast-spec/tests/AssignmentOperatorToText.test.ts
new file mode 100644
index 000000000000..867eec016ef4
--- /dev/null
+++ b/packages/ast-spec/tests/AssignmentOperatorToText.test.ts
@@ -0,0 +1,11 @@
+import type { AssignmentOperator } from 'typescript';
+
+import { AssignmentOperatorToText } from '../src';
+
+// @ts-expect-error: purposely unused
+type _Test = {
+  readonly [T in AssignmentOperator]: AssignmentOperatorToText[T];
+  // If there are any AssignmentOperator members that don't have a corresponding
+  // AssignmentOperatorToText, then this line will error with "Type 'T' cannot
+  // be used to index type 'AssignmentOperatorToText'."
+};