diff --git a/lib/member_builder.js b/lib/member_builder.js
index d7c4c53..4cc138b 100644
--- a/lib/member_builder.js
+++ b/lib/member_builder.js
@@ -66,23 +66,26 @@ exports.buildMethod = function( members, meta, name, value, keywords )
 {
     var prev = scanMembers( members, name );
 
-    // disallow overriding properties with methods
-    if ( prev && !( prev instanceof Function ) )
+    if ( prev )
     {
-        throw new TypeError(
-            "Cannot override property '" + name + "' with method"
-        );
-    }
+        // disallow overriding properties with methods
+        if ( !( prev instanceof Function ) )
+        {
+            throw new TypeError(
+                "Cannot override property '" + name + "' with method"
+            );
+        }
 
-    // ensure parameter list is at least the length of its supertype
-    if ( prev && (
-        ( value.__length || value.length ) < ( prev.__length || prev.length )
-    ) )
-    {
-        throw new TypeError(
-            "Declaration of method '" + name + "' must be compatiable " +
-                "with that of its supertype"
-        );
+        // ensure parameter list is at least the length of its supertype
+        if ( ( value.__length || value.length )
+            < ( prev.__length || prev.length )
+        )
+        {
+            throw new TypeError(
+                "Declaration of method '" + name + "' must be compatiable " +
+                    "with that of its supertype"
+            );
+        }
     }
 
     var dest = getMemberVisibility( members, keywords );