diff --git a/test/helpers/sinon.js b/test/helpers/sinon.js
index c3612021b..398a2e36c 100644
--- a/test/helpers/sinon.js
+++ b/test/helpers/sinon.js
@@ -1708,16 +1708,16 @@ var sinon = (function (formatio) {
             var args = slice.call(arguments, 1);
             var formatter;
 
-            return (format || "").replace(/%(.)/g, function (match, specifyer) {
-                formatter = spyApi.formatters[specifyer];
+            return (format || "").replace(/%(.)/g, function (match, specifier) {
+                formatter = spyApi.formatters[specifier];
 
                 if (typeof formatter == "function") {
                     return formatter.call(null, spy, args);
-                } else if (!isNaN(parseInt(specifyer, 10))) {
-                    return sinon.format(args[specifyer - 1]);
+                } else if (!isNaN(parseInt(specifier, 10))) {
+                    return sinon.format(args[specifier - 1]);
                 }
 
-                return "%" + specifyer;
+                return "%" + specifier;
             });
         }
     };