diff --git a/Sources/KeyPath+Querying.swift b/Sources/KeyPath+Querying.swift
index 9893789..25b549c 100644
--- a/Sources/KeyPath+Querying.swift
+++ b/Sources/KeyPath+Querying.swift
@@ -325,6 +325,11 @@ public func == <O, D>(_ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>,
     return Where<O>(O.meta[keyPath: keyPath].keyPath, isEqualTo: object)
 }
 
+public func == <O, D>(_ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>, _ null: Void?) -> Where<O> {
+    
+    return Where<O>(O.meta[keyPath: keyPath].keyPath, isEqualTo: nil)
+}
+
 public func != <O, D>(_ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>, _ object: D) -> Where<O> {
     
     return !Where<O>(O.meta[keyPath: keyPath].keyPath, isEqualTo: object)
@@ -335,6 +340,11 @@ public func != <O, D>(_ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>,
     return !Where<O>(O.meta[keyPath: keyPath].keyPath, isEqualTo: object)
 }
 
+public func != <O, D>(_ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>, _ null: Void?) -> Where<O> {
+    
+    return !Where<O>(O.meta[keyPath: keyPath].keyPath, isEqualTo: nil)
+}
+
 public func ~= <O, D, S: Sequence>(_ sequence: S, _ keyPath: KeyPath<O, RelationshipContainer<O>.ToOne<D>>) -> Where<O> where S.Iterator.Element == D {
     
     return Where<O>(O.meta[keyPath: keyPath].keyPath, isMemberOf: sequence)