diff --git a/lib/string-utils.ts b/lib/string-utils.ts
index 732e82a7..16e73223 100644
--- a/lib/string-utils.ts
+++ b/lib/string-utils.ts
@@ -1,5 +1,12 @@
 export function camelCase (str: string): string {
-  str = str.toLocaleLowerCase()
+  // Handle the case where an argument is provided as camel case, e.g., fooBar.
+  // by ensuring that the string isn't already mixed case:
+  const isCamelCase = str !== str.toLowerCase() && str !== str.toUpperCase()
+
+  if (!isCamelCase) {
+    str = str.toLocaleLowerCase()
+  }
+
   if (str.indexOf('-') === -1 && str.indexOf('_') === -1) {
     return str
   } else {
@@ -14,7 +21,6 @@ export function camelCase (str: string): string {
       }
       if (i !== 0 && (chr === '-' || chr === '_')) {
         nextChrUpper = true
-        continue
       } else if (chr !== '-' && chr !== '_') {
         camelcase += chr
       }
diff --git a/test/string-utils.cjs b/test/string-utils.cjs
index 1129777c..74d618d4 100644
--- a/test/string-utils.cjs
+++ b/test/string-utils.cjs
@@ -11,6 +11,12 @@ describe('string-utils', function () {
     it('removes leading hyphens', () => {
       strictEqual(camelCase('-goodnight-moon'), 'goodnightMoon')
     })
+    it('camelCase string stays as is', () => {
+      strictEqual(camelCase('iAmCamelCase'), 'iAmCamelCase')
+    })
+    it('uppercase string with underscore to camel case', () => {
+      strictEqual(camelCase('NODE_VERSION'), 'nodeVersion')
+    })
   })
   describe('decamelize', () => {
     it('adds hyphens back to camelcase string', () => {