diff --git a/types/semver/index.d.ts b/types/semver/index.d.ts
index 5475b8af6c..e0dd2dcbad 100644
--- a/types/semver/index.d.ts
+++ b/types/semver/index.d.ts
@@ -31,6 +31,11 @@ export function clean(version: string, optionsOrLoose?: boolean | Options): stri
  * Return the version incremented by the release type (major, minor, patch, or prerelease), or null if it's not valid.
  */
 export function inc(v: string | SemVer, release: ReleaseType, optionsOrLoose?: boolean | Options, identifier?: string): string | null;
+export function inc(
+  v: string | SemVer,
+  release: ReleaseType,
+  identifier?: string,
+): string | null;
 /**
  * Return the major version number.
  */
diff --git a/types/semver/semver-tests.ts b/types/semver/semver-tests.ts
index 785afe4045..38a7579e8d 100644
--- a/types/semver/semver-tests.ts
+++ b/types/semver/semver-tests.ts
@@ -38,6 +38,7 @@ strn = semver.inc(str, "patch", loose);
 strn = semver.inc(str, "prepatch", loose);
 strn = semver.inc(str, "prerelease", loose);
 strn = semver.inc(str, "prerelease", loose, "alpha");
+strn = semver.inc(str, 'prerelease', 'beta');
 num = semver.major(str, loose);
 num = semver.minor(str, loose);
 num = semver.patch(str, loose);