diff --git a/src/Illuminate/Routing/Route.php b/src/Illuminate/Routing/Route.php
index f09d7fafaebd..f23d75d7a5d2 100755
--- a/src/Illuminate/Routing/Route.php
+++ b/src/Illuminate/Routing/Route.php
@@ -551,7 +551,7 @@ public function bindParameters(Request $request)
             );
         }
 
-        return $this->parameters = $this->replaceDefaults($params);
+        return $this->parameters = $this->fillDefaults($this->replaceDefaults($params));
     }
 
     /**
@@ -615,6 +615,23 @@ protected function replaceDefaults(array $parameters)
         return $parameters;
     }
 
+    /**
+     * Fill missing parameters with their defaults.
+     *
+     * @param  array  $parameters
+     * @return array
+     */
+    protected function fillDefaults(array $parameters)
+    {
+        foreach ($this->defaults as $key => $value) {
+            if (! isset($parameters[$key])) {
+                $parameters[$key] = $value;
+            }
+        }
+
+        return $parameters;
+    }
+
     /**
      * Parse the route action into a standard array.
      *