diff --git a/lib/assertions/is-function.js b/lib/assertions/is-function.js
index 0d613e2d..fe3a82a9 100644
--- a/lib/assertions/is-function.js
+++ b/lib/assertions/is-function.js
@@ -11,7 +11,9 @@ module.exports = function(referee) {
         expectation: "toBeFunction",
         values: function(actual, message) {
             return {
-                actual: String(actual).replace("\n", ""),
+                actual: String(actual)
+                    .replace("function(", "function (")
+                    .replace("\n", ""),
                 actualType: typeof actual,
                 customMessage: message
             };