diff --git a/lib/main.js b/lib/main.js
index 3d43efc..56f4cd6 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -21,7 +21,7 @@
 // MODULES //
 
 var isString = require( '@stdlib/assert-is-string' ).isPrimitive;
-var format = require( '@stdlib/string-format' );
+var format = require( '@stdlib/error-tools-fmtprodmsg' );
 var base = require( '@stdlib/string-base-startcase' );
 
 
@@ -40,7 +40,7 @@ var base = require( '@stdlib/string-base-startcase' );
 */
 function startcase( str ) {
 	if ( !isString( str ) ) {
-		throw new TypeError( format( 'invalid argument. Must provide a string. Value: `%s`.', str ) );
+		throw new TypeError( format( '1PX3B', str ) );
 	}
 	return base( str );
 }
diff --git a/package.json b/package.json
index 341b321..cbdac1b 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
     "@stdlib/process-read-stdin": "^0.2.2",
     "@stdlib/streams-node-stdin": "^0.2.3",
     "@stdlib/string-base-startcase": "^0.2.3",
-    "@stdlib/string-format": "^0.2.3",
+    "@stdlib/error-tools-fmtprodmsg": "^0.2.3",
     "@stdlib/error-tools-fmtprodmsg": "^0.2.3"
   },
   "devDependencies": {