diff --git a/lib/normalize.coffee b/lib/normalize.coffee
index 48bad3a..9138d3f 100644
--- a/lib/normalize.coffee
+++ b/lib/normalize.coffee
@@ -68,7 +68,7 @@ normalizers.default = (input, normType) ->
 
     r = stringToRegexp(input)
     if r isnt false
-      vals.push({'$regex' : r})
+      vals.push(r)
 
     return vals
   return input
@@ -90,7 +90,7 @@ normalizers.date = (input, normType) ->
 normalizers.string = (input, normType) ->
   if normType is 'query'
     if (m = /^\/(.*?)\/(g?i?m?y?)$/.exec(input))
-      return [{'$regex' : new RegExp(m[1], m[2])}, input]
+      return [new RegExp(m[1], m[2]), input]
   return input
 
 
@@ -124,7 +124,7 @@ normalizers.mac = (input, normType) ->
   if input.length == 17
     return [input, input.toLowerCase()]
 
-  return {'$regex' : new RegExp(input, 'i')}
+  return new RegExp(input, 'i')
 
 
 exports.normalize = (path, value, normType) ->
diff --git a/lib/query.coffee b/lib/query.coffee
index 5db57ac..8282e3e 100644
--- a/lib/query.coffee
+++ b/lib/query.coffee
@@ -51,8 +51,17 @@ expandValue = (param, value) ->
   while i < indices.length
     obj = {}
     for i in [0...keys.length]
+      if common.typeOf(values[i][indices[i]]) is common.REGEXP_TYPE
+        if keys[i] == '$ne'
+          obj['$not'] = values[i][indices[i]]
+          continue
+      else if keys[i] == '$not' and common.typeOf(values[i][indices[i]]) isnt common.OBJECT_TYPE
+        # Only a regex or decoument (object) are allowed within a $not operator.
+        # This is needed in order to discard string from which a regex is generated.
+        continue
+
       obj[keys[i]] = values[i][indices[i]]
-    objs.push(obj)
+    objs.push(obj) if Object.keys(obj).length
 
     for i in [0...indices.length]
       indices[i] += 1
@@ -75,7 +84,7 @@ permute = (param, val, aliases) ->
     values = expandValue(k, val)
     if k[k.lastIndexOf('.') + 1] != '_'
       k += '._value'
-  
+
     for v in values
       obj = {}
       obj[k] = v
@@ -96,7 +105,7 @@ expand = (query, aliases) ->
       conditions = permute(k, v, aliases)
       if conditions.length > 1
         new_query['$and'] ?= []
-        if v?['$ne']?
+        if v?['$ne']? or v?['$nin']? or v?['$not']?
           for c in conditions
             new_query['$and'].push(c)
         else