diff --git a/index.js b/index.js
index d003297a..98ee7ae2 100644
--- a/index.js
+++ b/index.js
@@ -696,7 +696,7 @@ function parse (args, opts) {
         })
         // For "--optionName", also set argv['option-name']
         flags.aliases[key].concat(key).forEach(function (x) {
-          if (/[A-Z]/.test(x) && configuration['camel-case-expansion']) {
+          if (x.length > 1 && /[A-Z]/.test(x) && configuration['camel-case-expansion']) {
             var c = decamelize(x, '-')
             if (c !== key && flags.aliases[key].indexOf(c) === -1) {
               flags.aliases[key].push(c)
diff --git a/test/yargs-parser.js b/test/yargs-parser.js
index 7b52a0be..b0e8555b 100644
--- a/test/yargs-parser.js
+++ b/test/yargs-parser.js
@@ -1218,6 +1218,21 @@ describe('yargs-parser', function () {
         result.should.have.property('someOption', 'asdf')
       })
 
+      it('should not apply camel-case logic to 1-character options', function () {
+        var result = parser(['-p', 'hello'], {
+          alias: {
+            p: 'parallel',
+            P: 'parallel-series'
+          }
+        })
+
+        result.should.not.have.property('P', 'hello')
+        result.should.not.have.property('parallel-series', 'hello')
+        result.should.not.have.property('parallelSeries', 'hello')
+        result.should.have.property('parallel', 'hello')
+        result.should.have.property('p', 'hello')
+      })
+
       it('should provide aliases of options with dashes as camelCase properties', function () {
         var result = parser([], {
           alias: {