diff --git a/lib/yargs-parser.ts b/lib/yargs-parser.ts
index 73f91e10..651c5c32 100644
--- a/lib/yargs-parser.ts
+++ b/lib/yargs-parser.ts
@@ -318,7 +318,7 @@ export class YargsParser {
         for (let j = 0; j < letters.length; j++) {
           next = arg.slice(j + 2)
 
-          if (letters[j + 1] && letters[j + 1] === '=') {
+          if ((letters[j + 1] && letters[j + 1] === '=') || next === '=') {
             value = arg.slice(j + 3)
             key = letters[j]
 
diff --git a/test/yargs-parser.mjs b/test/yargs-parser.mjs
index 4d94237c..87baad0d 100644
--- a/test/yargs-parser.mjs
+++ b/test/yargs-parser.mjs
@@ -186,6 +186,12 @@ describe('yargs-parser', function () {
     parse.should.have.property('_').with.length(0)
   })
 
+  it('should set a short option to an empty string when a trailing equals sign supplies no value', function () {
+    parser(['-o='], { alias: { o: 'opt' } }).should.deep.equal({ _: [], o: '', opt: '' })
+    // control: a non-empty value after the equals sign is unaffected
+    parser(['-o=x'], { alias: { o: 'opt' } }).should.deep.equal({ _: [], o: 'x', opt: 'x' })
+  })
+
   it('should not set the next value as the value of a short option if that option is explicitly defined as a boolean', function () {
     const parse = parser(['-t', 'moo'], {
       boolean: 't'