diff --git a/lib/node_modules/@stdlib/string/base/percent-encode/lib/main.js b/lib/node_modules/@stdlib/string/base/percent-encode/lib/main.js
index cad0ac487884..08e4da28c034 100644
--- a/lib/node_modules/@stdlib/string/base/percent-encode/lib/main.js
+++ b/lib/node_modules/@stdlib/string/base/percent-encode/lib/main.js
@@ -20,6 +20,7 @@
 
 // MODULES //
 
+var uppercase = require( '@stdlib/string/base/uppercase' );
 var utf16ToUTF8Array = require( '@stdlib/string/utf16-to-utf8-array' );
 
 
@@ -88,7 +89,7 @@ function percentEncode( str ) {
 			out += str.charAt( i );
 		} else {
 			// Convert an octet to hexadecimal and uppercase according to the RFC (see https://tools.ietf.org/html/rfc3986#section-2.1):
-			out += '%' + byte.toString( 16 ).toUpperCase();
+			out += '%' + uppercase( byte.toString( 16 ) );
 		}
 	}
 	return out;