diff --git a/classes/semver.js b/classes/semver.js
index 97049a40..6fbc062b 100644
--- a/classes/semver.js
+++ b/classes/semver.js
@@ -1,6 +1,6 @@
 const debug = require('../internal/debug')
 const { MAX_LENGTH, MAX_SAFE_INTEGER } = require('../internal/constants')
-const { safeRe: re, t } = require('../internal/re')
+const { safeRe: re, safeSrc: src, t } = require('../internal/re')
 
 const parseOptions = require('../internal/parse-options')
 const { compareIdentifiers } = require('../internal/identifiers')
@@ -182,7 +182,8 @@ class SemVer {
       }
       // Avoid an invalid semver results
       if (identifier) {
-        const match = `-${identifier}`.match(this.options.loose ? re[t.PRERELEASELOOSE] : re[t.PRERELEASE])
+        const r = new RegExp(`^${this.options.loose ? src[t.PRERELEASELOOSE] : src[t.PRERELEASE]}$`)
+        const match = `-${identifier}`.match(r)
         if (!match || match[1] !== identifier) {
           throw new Error(`invalid identifier: ${identifier}`)
         }
diff --git a/internal/re.js b/internal/re.js
index fd8920e7..2a956ba0 100644
--- a/internal/re.js
+++ b/internal/re.js
@@ -10,6 +10,7 @@ exports = module.exports = {}
 const re = exports.re = []
 const safeRe = exports.safeRe = []
 const src = exports.src = []
+const safeSrc = exports.safeSrc = []
 const t = exports.t = {}
 let R = 0
 
@@ -42,6 +43,7 @@ const createToken = (name, value, isGlobal) => {
   debug(name, index, value)
   t[name] = index
   src[index] = value
+  safeSrc[index] = safe
   re[index] = new RegExp(value, isGlobal ? 'g' : undefined)
   safeRe[index] = new RegExp(safe, isGlobal ? 'g' : undefined)
 }
diff --git a/test/fixtures/increments.js b/test/fixtures/increments.js
index a9b06358..f0839df5 100644
--- a/test/fixtures/increments.js
+++ b/test/fixtures/increments.js
@@ -32,6 +32,7 @@ module.exports = [
   ['1.2.3-alpha.9.beta', 'prerelease', '1.2.3-alpha.10.beta'],
   ['1.2.3-alpha.10.beta', 'prerelease', '1.2.3-alpha.11.beta'],
   ['1.2.3-alpha.11.beta', 'prerelease', '1.2.3-alpha.12.beta'],
+  ['1.0.0', 'prepatch', '1.0.1-alpha.1.1a.0', null, 'alpha.1.1a'],
   ['1.2.0', 'prepatch', '1.2.1-0'],
   ['1.2.0-1', 'prepatch', '1.2.1-0'],
   ['1.2.0', 'preminor', '1.3.0-0'],
diff --git a/test/internal/re.js b/test/internal/re.js
index 2851b325..1db0586a 100644
--- a/test/internal/re.js
+++ b/test/internal/re.js
@@ -1,15 +1,18 @@
 const { test } = require('tap')
-const { src, re, safeRe } = require('../../internal/re')
+const { src, re, safeRe, safeSrc } = require('../../internal/re')
 const semver = require('../../')
 
-test('has a list of src, re, and tokens', (t) => {
+test('Semver itself has a list of src, re, and tokens', (t) => {
   t.match(Object.assign({}, semver), {
-    src: Array,
     re: Array,
+    src: Array,
     tokens: Object,
   })
   re.forEach(r => t.match(r, RegExp, 'regexps are regexps'))
-  src.forEach(s => t.match(s, String, 'src is strings'))
+  safeRe.forEach(r => t.match(r, RegExp, 'safe regexps are regexps'))
+  src.forEach(s => t.match(s, String, 'src are strings'))
+  safeSrc.forEach(s => t.match(s, String, 'safe srcare strings'))
+  t.ok(Object.keys(semver.tokens).length, 'there are tokens')
   for (const i in semver.tokens) {
     t.match(semver.tokens[i], Number, 'tokens are numbers')
   }