diff --git a/src/index.ts b/src/index.ts
index e4082837..6d09cf8d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -15,6 +15,8 @@ export {
   isNode,
   isPair,
   isScalar,
+  isMergeKey,
+  MERGE_KEY,
   isSeq
 } from './nodes/identity.ts'
 export type { Node, ParsedNode, Range } from './nodes/Node.ts'
diff --git a/src/nodes/identity.ts b/src/nodes/identity.ts
index 9f1fba2f..f98099dd 100644
--- a/src/nodes/identity.ts
+++ b/src/nodes/identity.ts
@@ -6,6 +6,8 @@ import type { Scalar } from './Scalar.ts'
 import type { YAMLMap } from './YAMLMap.ts'
 import type { YAMLSeq } from './YAMLSeq.ts'
 
+export { isMergeKey, MERGE_KEY } from '../schema/yaml-1.1/merge.ts'
+
 export const ALIAS: unique symbol = Symbol.for('yaml.alias')
 export const DOC: unique symbol = Symbol.for('yaml.document')
 export const MAP: unique symbol = Symbol.for('yaml.map')
diff --git a/src/schema/yaml-1.1/merge.ts b/src/schema/yaml-1.1/merge.ts
index e8f449ac..ff0350c0 100644
--- a/src/schema/yaml-1.1/merge.ts
+++ b/src/schema/yaml-1.1/merge.ts
@@ -12,7 +12,7 @@ import type { ScalarTag } from '../types.ts'
 // Keys in mapping nodes earlier in the sequence override keys specified in
 // later mapping nodes. -- http://yaml.org/type/merge.html
 
-const MERGE_KEY = '<<'
+export const MERGE_KEY = '<<'
 
 export const merge: ScalarTag & {
   identify(value: unknown): boolean
@@ -23,7 +23,7 @@ export const merge: ScalarTag & {
     (typeof value === 'symbol' && value.description === MERGE_KEY),
   default: 'key',
   tag: 'tag:yaml.org,2002:merge',
-  test: /^<<$/,
+  test: new RegExp(`^${MERGE_KEY}$`),
   resolve: () =>
     Object.assign(new Scalar(Symbol(MERGE_KEY)), {
       addToJSMap: addMergeToJSMap