diff --git a/lib/main.js b/lib/main.js
index be0ef10..a71f608 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -24,7 +24,7 @@ var isArray = require( '@stdlib/assert-is-array' );
 var isCollection = require( '@stdlib/assert-is-collection' );
 var isTypedArrayLike = require( '@stdlib/assert-is-typed-array-like' );
 var isInteger = require( '@stdlib/assert-is-integer' );
-var format = require( '@stdlib/string-format' );
+var format = require( '@stdlib/error-tools-fmtprodmsg' );
 var appendArray = require( './append_array.js' );
 var appendObject = require( './append_object.js' );
 var appendTypedArray = require( './append_typed_array.js' );
@@ -56,7 +56,7 @@ var appendTypedArray = require( './append_typed_array.js' );
 */
 function append( collection1, collection2 ) {
 	if ( !isCollection( collection2 ) ) {
-		throw new TypeError( format( 'invalid argument. Second argument must be an array-like object. Value: `%s`.', collection2 ) );
+		throw new TypeError( format( '1Ql2y', collection2 ) );
 	}
 	if ( isArray( collection1 ) ) {
 		return appendArray( collection1, collection2 );
@@ -75,7 +75,7 @@ function append( collection1, collection2 ) {
 	) {
 		return appendObject( collection1, collection2 );
 	}
-	throw new TypeError( format( 'invalid argument. First argument must be either an array, typed array, or an array-like object. Value: `%s`.', collection1 ) );
+	throw new TypeError( format( '1QlAi', collection1 ) );
 }
 
 
diff --git a/package.json b/package.json
index e5769bd..a88d9d3 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,7 @@
     "@stdlib/assert-is-integer": "^0.2.3",
     "@stdlib/assert-is-typed-array-like": "^0.2.3",
     "@stdlib/math-base-special-ceil2": "^0.3.1",
-    "@stdlib/string-format": "^0.2.3",
+    "@stdlib/error-tools-fmtprodmsg": "^0.2.3",
     "@stdlib/types": "^0.5.1",
     "@stdlib/error-tools-fmtprodmsg": "^0.2.3"
   },