diff --git a/README.md b/README.md
index df54e7a0..7dde5f8c 100644
--- a/README.md
+++ b/README.md
@@ -513,6 +513,40 @@ ex.
 * `s.clean('      2.1.5   ')`: `'2.1.5'`
 * `s.clean('~1.0.0')`: `null`
 
+## Constants
+
+As a convenience, helper constants are exported to provide information about what `node-semver` supports:
+
+### `RELEASE_TYPES`
+
+- major
+- premajor
+- minor
+- preminor
+- patch
+- prepatch
+- prerelease
+
+```
+const semver = require('semver');
+
+if (semver.RELEASE_TYPES.includes(arbitraryUserInput)) {
+  console.log('This is a valid release type!');
+} else {
+  console.warn('This is NOT a valid release type!');
+}
+```
+
+### `SEMVER_SPEC_VERSION`
+
+2.0.0
+
+```
+const semver = require('semver');
+
+console.log('We are currently using the semver specification version:', semver.SEMVER_SPEC_VERSION);
+```
+
 ## Exported Modules
 
 <!--
@@ -566,3 +600,4 @@ The following modules are available:
 * `require('semver/ranges/outside')`
 * `require('semver/ranges/to-comparators')`
 * `require('semver/ranges/valid')`
+
diff --git a/index.js b/index.js
index 4a342c6a..86d42ac1 100644
--- a/index.js
+++ b/index.js
@@ -83,6 +83,7 @@ module.exports = {
   src: internalRe.src,
   tokens: internalRe.t,
   SEMVER_SPEC_VERSION: constants.SEMVER_SPEC_VERSION,
+  RELEASE_TYPES: constants.RELEASE_TYPES,
   compareIdentifiers: identifiers.compareIdentifiers,
   rcompareIdentifiers: identifiers.rcompareIdentifiers,
 }
diff --git a/internal/constants.js b/internal/constants.js
index 4f0de59b..cb2d76c2 100644
--- a/internal/constants.js
+++ b/internal/constants.js
@@ -9,9 +9,20 @@ const MAX_SAFE_INTEGER = Number.MAX_SAFE_INTEGER ||
 // Max safe segment length for coercion.
 const MAX_SAFE_COMPONENT_LENGTH = 16
 
+const RELEASE_TYPES = [
+  'major',
+  'premajor',
+  'minor',
+  'preminor',
+  'patch',
+  'prepatch',
+  'prerelease',
+]
+
 module.exports = {
-  SEMVER_SPEC_VERSION,
   MAX_LENGTH,
-  MAX_SAFE_INTEGER,
   MAX_SAFE_COMPONENT_LENGTH,
+  MAX_SAFE_INTEGER,
+  RELEASE_TYPES,
+  SEMVER_SPEC_VERSION,
 }
diff --git a/test/internal/constants.js b/test/internal/constants.js
index 1b72d870..a8f6ab2d 100644
--- a/test/internal/constants.js
+++ b/test/internal/constants.js
@@ -2,8 +2,9 @@ const t = require('tap')
 const constants = require('../../internal/constants')
 
 t.match(constants, {
-  SEMVER_SPEC_VERSION: String,
   MAX_LENGTH: Number,
-  MAX_SAFE_INTEGER: Number,
   MAX_SAFE_COMPONENT_LENGTH: Number,
-}, 'got some numbers exported')
+  MAX_SAFE_INTEGER: Number,
+  RELEASE_TYPES: Array,
+  SEMVER_SPEC_VERSION: String,
+}, 'got appropriate data types exported')